| Message ID | 20201224150402.1945788-3-dwlsalmeida@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
Em Thu, 24 Dec 2020 12:04:02 -0300 "Daniel W. S. Almeida" <dwlsalmeida@gmail.com> escreveu: > From: "Daniel W. S. Almeida" <dwlsalmeida@gmail.com> > > Add a debugfs interface for testing purposes that can be enabled > by selecting **DVB_VIDTV_DEBUGFS**. This makes it possible to: > > dynamically inject errors at runtime by interacting with the files > at /sys/kernel/debug/vidtv/* > > read some dvbv5 statistics from userspace more easily. > > This is entirely optional and the driver will work without this option > selected. Patches 1 and 2 on this series seem OK. I'm applying them, after testing. Please see the notes below for this one. > > Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com> > --- > .../driver-api/media/drivers/vidtv.rst | 80 +++--- > drivers/media/test-drivers/vidtv/Kconfig | 13 + > .../media/test-drivers/vidtv/vidtv_bridge.c | 13 + > .../media/test-drivers/vidtv/vidtv_bridge.h | 2 + > .../media/test-drivers/vidtv/vidtv_debugfs.h | 42 +++ > drivers/media/test-drivers/vidtv/vidtv_mux.c | 272 ++++++++++++++++++ > drivers/media/test-drivers/vidtv/vidtv_mux.h | 7 + > drivers/media/test-drivers/vidtv/vidtv_ts.c | 8 + > drivers/media/test-drivers/vidtv/vidtv_ts.h | 8 + > 9 files changed, 412 insertions(+), 33 deletions(-) > create mode 100644 drivers/media/test-drivers/vidtv/vidtv_debugfs.h > > diff --git a/Documentation/driver-api/media/drivers/vidtv.rst b/Documentation/driver-api/media/drivers/vidtv.rst > index 673bdff919ea..e7c450289774 100644 > --- a/Documentation/driver-api/media/drivers/vidtv.rst > +++ b/Documentation/driver-api/media/drivers/vidtv.rst > @@ -227,6 +227,9 @@ vidtv_mux.[ch] > #. Delivering the resulting TS packets to the bridge > driver so it can pass them to the demux. > > +vidtv_debugfs.h > + Exposes data structures used in vidtv's debugfs interface. > + > Testing vidtv with v4l-utils > ---------------------------- > > @@ -431,27 +434,53 @@ For more information on dvb-zap check its online documentation here: > See also: `zap <https://www.linuxtv.org/wiki/index.php/Zap>`_. > > > -What can still be improved in vidtv > ------------------------------------ > +Vidtv *debugfs* integration > +___________________________ > + > +Vidtv now comes with a *debugfs* interface that can be enabled by selecting > +**DVB_VIDTV_DEBUGFS**. Using it, one can "now comes" -> "can be compiled" > + > +#. dynamically inject errors at runtime by interacting with the files at /sys/kernel/debug/vidtv/* > + > +#. read some dvbv5 statistics from userspace more easily > + > +.. note:: > + This is entirely optional and the driver will work without this option selected. Please keep lines <= 80 columns, except when there's a strong reason to use longer lines. The same applies to other parts of this patch. > + > +At boot, vidtv will set up a directory per simulated frontend. Here is a list of > +created files and their associated functionality once they are written to: > + > +noise > + The probability of adding random noise in the packets (0 - 10000). > +drop > + Drop n packets at random > +shl > + Shift left n bytes at random > +shr > + Shift right n bytes at random > +discontinuity > + Create n discontinuities at random. This means artificially increasing > + the continuity counters such that a discontinuity error is generated. > + > +Another option is to provide a probability of such events ocurring. Drop, shl, > +shr, and discontinuity have versions that take in a probability in the [0, > +10000] range. > > -Add *debugfs* integration > -~~~~~~~~~~~~~~~~~~~~~~~~~ > +Writing to the files at the frontend directory will target all packets in the > +mux buffer. Alternatively, vidtv will also create a directory per PID. Writing > +to these files will, in turn, only affect that particular PID. > > -Although frontend drivers provide DVBv5 statistics via the .read_status > -call, a nice addition would be to make additional statistics available to > -userspace via debugfs, which is a simple-to-use, RAM-based filesystem > -specifically designed for debug purposes. > > -The logic for this would be implemented on a separate file so as not to > -pollute the frontend driver. These statistics are driver-specific and can > -be useful during tests. > +What can still be improved in vidtv > +----------------------------------- > + > +Improve debugfs support > +~~~~~~~~~~~~~~~~~~~~~~~ > > -The Siano driver is one example of a driver using > -debugfs to convey driver-specific statistics to userspace and it can be > -used as a reference. > +Vidtv offers support for dynamically injecting errors and retrieving some dvbv5 > +stats via *debugfs*. This can be improved upon to add new ways of testing from > +userspace. > > -This should be further enabled and disabled via a Kconfig > -option for convenience. > > Add a way to test video > ~~~~~~~~~~~~~~~~~~~~~~~ > @@ -468,23 +497,6 @@ which resides at:: > drivers/media/common/v4l2-tpg/ > > > -Add white noise simulation > -~~~~~~~~~~~~~~~~~~~~~~~~~~ > - > -The vidtv tuner already has code to identify whether the chosen frequency > -is too far away from a table of valid frequencies. For now, this means that > -the demodulator can eventually lose the lock on the signal, since the tuner will > -report a bad signal quality. > - > -A nice addition is to simulate some noise when the signal quality is bad by: > - > -- Randomly dropping some TS packets. This will trigger a continuity error if the > - continuity counter is updated but the packet is not passed on to the demux. > - > -- Updating the error statistics accordingly (e.g. BER, etc). > - > -- Simulating some noise in the encoded data. > - > Functions and structs used within vidtv > --------------------------------------- > > @@ -511,3 +523,5 @@ Functions and structs used within vidtv > .. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_common.c > > .. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_tuner.c > + > +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_debugfs.h > diff --git a/drivers/media/test-drivers/vidtv/Kconfig b/drivers/media/test-drivers/vidtv/Kconfig > index 22c4fd39461f..05513f1c67e1 100644 > --- a/drivers/media/test-drivers/vidtv/Kconfig > +++ b/drivers/media/test-drivers/vidtv/Kconfig > @@ -8,4 +8,17 @@ config DVB_VIDTV > working on userspace applications. > > > + When in doubt, say N. > + > +config DVB_VIDTV_DEBUGFS > + bool "Enable debugfs for vidtv" > + depends on DVB_VIDTV > + depends on DEBUG_FS > + > + help > + Choose Y to enable the vidtv debugfs interface. Currently allows for > + dynamically introducing errors in the generated MPEG Transport Stream > + for testing purposes. > + > + > When in doubt, say N. > diff --git a/drivers/media/test-drivers/vidtv/vidtv_bridge.c b/drivers/media/test-drivers/vidtv/vidtv_bridge.c > index fc64d0c8492a..d5ebe680724f 100644 > --- a/drivers/media/test-drivers/vidtv/vidtv_bridge.c > +++ b/drivers/media/test-drivers/vidtv/vidtv_bridge.c > @@ -10,6 +10,7 @@ > * Copyright (C) 2020 Daniel W. S. Almeida > */ > > +#include <linux/debugfs.h> > #include <linux/dev_printk.h> > #include <linux/moduleparam.h> > #include <linux/mutex.h> > @@ -172,6 +173,7 @@ static int vidtv_start_streaming(struct vidtv_dvb *dvb) > .transport_stream_id = VIDTV_DEFAULT_TS_ID, > .network_id = VIDTV_DEFAULT_NETWORK_ID, > .network_name = VIDTV_DEFAULT_NETWORK_NAME, > + .debugfs_root = dvb->debugfs_root, > .priv = dvb, > }; > struct device *dev = &dvb->pdev->dev; > @@ -485,6 +487,7 @@ static int vidtv_bridge_dvb_init(struct vidtv_dvb *dvb) > static int vidtv_bridge_probe(struct platform_device *pdev) > { > struct vidtv_dvb *dvb; > + struct dentry *debugfs_root; > int ret; > > dvb = kzalloc(sizeof(*dvb), GFP_KERNEL); > @@ -501,6 +504,12 @@ static int vidtv_bridge_probe(struct platform_device *pdev) > > platform_set_drvdata(pdev, dvb); > > +#ifdef CONFIG_DVB_VIDTV_DEBUGFS > + debugfs_root = debugfs_create_dir("vidtv", NULL); > + if (!IS_ERR(debugfs_root)) > + dvb->debugfs_root = debugfs_root; > +#endif //CONFIG_DVB_VIDTV_DEBUGFS > + While C99 comments are now allowed, we still prefer to use C89 ones: #endif /* CONFIG_DVB_VIDTV_DEBUGFS */ (also, please add a space after the comment tag, as it makes easier for read the comment) > dev_info(&pdev->dev, "Successfully initialized vidtv!\n"); > return ret; > > @@ -516,6 +525,10 @@ static int vidtv_bridge_remove(struct platform_device *pdev) > > dvb = platform_get_drvdata(pdev); > > +#ifdef CONFIG_DVB_VIDTV_DEBUGFS > + debugfs_remove_recursive(dvb->debugfs_root); > +#endif //CONFIG_DVB_VIDTV_DEBUGFS > + > mutex_destroy(&dvb->feed_lock); > > for (i = 0; i < NUM_FE; ++i) { > diff --git a/drivers/media/test-drivers/vidtv/vidtv_bridge.h b/drivers/media/test-drivers/vidtv/vidtv_bridge.h > index 2528adaee27d..9ef37d8ad2cc 100644 > --- a/drivers/media/test-drivers/vidtv/vidtv_bridge.h > +++ b/drivers/media/test-drivers/vidtv/vidtv_bridge.h > @@ -42,6 +42,7 @@ > * @feed_lock: Protects access to the start/stop stream logic/data. > * @streaming: Whether we are streaming now. > * @mux: The abstraction responsible for delivering MPEG TS packets to the bridge. > + * @debugfs_root: A handle to vidtv's debugfs directory > */ > struct vidtv_dvb { > struct platform_device *pdev; > @@ -60,6 +61,7 @@ struct vidtv_dvb { > bool streaming; > > struct vidtv_mux *mux; > + struct dentry *debugfs_root; > }; > > #endif // VIDTV_BRIDG_H > diff --git a/drivers/media/test-drivers/vidtv/vidtv_debugfs.h b/drivers/media/test-drivers/vidtv/vidtv_debugfs.h > new file mode 100644 > index 000000000000..1743fe6d96cf > --- /dev/null > +++ b/drivers/media/test-drivers/vidtv/vidtv_debugfs.h > @@ -0,0 +1,42 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Vidtv serves as a reference DVB driver and helps validate the existing APIs > + * in the media subsystem. It can also aid developers working on userspace > + * applications. > + * > + * Copyright (C) 2020 Daniel W. S. Almeida > + */ > + > +#ifndef VIDTV_DEBUGFS_H > +#define VIDTV_DEBUGFS_H > +#include <linux/debugfs.h> > + > +/** > + * struct vidtv_debugfs - Represents the vidtv debugfs interface > + * > + * @dir_dentry: A handle to the debugfs dentry > + * @noise: Probability of adding noise to a byte in a packet [0, 10000] > + * @drop: Drop n packets at random. > + * @drop_probability: Probability to randomly drop a packet [0, 10000] > + * @shl_probability: Probability to randomly shift left a byte in a packet [0, 10000] > + * @shr_probability: Probability to randomly shift right a byte in a packet [0, 10000] > + * @discontinuity_probability: Probability of artificially creating a > + * discontinuity error [0, 10000] > + * @shl: Shift n bytes left at random, i.e. byte[i] = byte[i] << 1; > + * @shr: Shift n bytes right at random, i.e. byte[i] = byte[i] >>1; > + * @discontinuity: Create n discontinuity errors > + */ > +struct vidtv_debugfs { > + struct dentry *dir_dentry; > + u32 noise; > + u32 drop_probability; > + u32 shl_probability; > + u32 shr_probability; > + u32 discontinuity_probability; > + u32 drop; > + u32 shl; > + u32 shr; > + u32 discontinuity; > +}; > + > +#endif //VIDTV_DEBUGFS_H > diff --git a/drivers/media/test-drivers/vidtv/vidtv_mux.c b/drivers/media/test-drivers/vidtv/vidtv_mux.c > index b51e6a3b8cbe..e6d69fe01908 100644 > --- a/drivers/media/test-drivers/vidtv/vidtv_mux.c > +++ b/drivers/media/test-drivers/vidtv/vidtv_mux.c > @@ -12,11 +12,14 @@ > * Copyright (C) 2020 Daniel W. S. Almeida > */ > > +#include "vidtv_debugfs.h" > +#include <linux/debugfs.h> > #include <linux/delay.h> > #include <linux/dev_printk.h> > #include <linux/jiffies.h> > #include <linux/kernel.h> > #include <linux/math64.h> > +#include <linux/random.h> > #include <linux/ratelimit.h> > #include <linux/slab.h> > #include <linux/types.h> > @@ -385,6 +388,204 @@ static void vidtv_mux_clear(struct vidtv_mux *m) > m->mux_buf_offset = 0; > } > > +static void vidtv_mux_add_random_noise(struct vidtv_mux *m, u32 noise_prob, u32 pkt_start) > +{ > + u8 noise; > + u8 *pkt = m->mux_buf + pkt_start; > + u32 i; > + > + for (i = 0; i < TS_PACKET_LEN; i++) > + if (prandom_u32_max(10000) < noise_prob) { > + noise = prandom_u32_max(0xff); > + pkt[i] = pkt[i] + noise; > + } > +} > + > +static void vidtv_mux_drop_random(struct vidtv_mux *m, u32 drop_prob, u32 pkt_start, u32 *nbytes) > +{ > + u8 *pkt = m->mux_buf + pkt_start; > + u8 *last_pkt = m->mux_buf + m->mux_buf_offset - TS_PACKET_LEN; > + u32 npkts = m->mux_buf_offset / 188; > + > + if (!npkts) > + return; > + > + if (prandom_u32_max(10000) < drop_prob) { > + if (npkts > 1 && pkt != last_pkt) { > + //overwrite victim with last packet > + memcpy(pkt, last_pkt, TS_PACKET_LEN); > + //remove last packet from buffer > + memset(last_pkt, 0, TS_PACKET_LEN); > + } else { > + //just erase it > + memset(pkt, 0, TS_PACKET_LEN); > + } > + > + //keep track of the loss of this packet > + m->mux_buf_offset -= TS_PACKET_LEN; > + *nbytes -= TS_PACKET_LEN; > + } > +} > + > +static void vidtv_mux_shl_random(struct vidtv_mux *m, u32 shl_prob, u32 pkt_start) > +{ > + u8 *pkt = m->mux_buf + pkt_start; > + /* select one of the 188 bytes at random */ > + u8 *byte = pkt + prandom_u32_max(TS_PACKET_LEN); > + > + if (prandom_u32_max(10000) < shl_prob) > + *byte = *byte << 1; > +} > + > +static void vidtv_mux_shr_random(struct vidtv_mux *m, u32 shr_prob, u32 pkt_start) > +{ > + u8 *pkt = m->mux_buf + pkt_start; > + /* select one of the 188 bytes at random */ > + u8 *byte = pkt + prandom_u32_max(TS_PACKET_LEN); > + > + if (prandom_u32_max(10000) < shr_prob) > + *byte = *byte >> 1; > +} > + > +static void vidtv_mux_discontinuity_random(struct vidtv_mux *m, u32 disc_prob, u16 pid) > +{ > + struct vidtv_mux_pid_ctx *ctx = vidtv_mux_get_pid_ctx(m, pid); > + > + /* if the pkt was previously corrupted such that we cannot retrieve its pid context > + * anymore, then bail > + */ > + if (!ctx) > + return; > + > + if (prandom_u32_max(10000) < disc_prob) > + vidtv_ts_inc_cc(&ctx->cc); > +} > + > +static u32 vidtv_mux_get_random_pkt_offset(struct vidtv_mux *m) > +{ > + u32 npkts = m->mux_buf_offset / TS_PACKET_LEN; > + u32 pkt_offset = prandom_u32_max(npkts) * TS_PACKET_LEN; > + > + return pkt_offset; > +} > + > +static u32 vidtv_mux_get_random_pkt_offset_for_pid(struct vidtv_mux *m, u16 pid, bool *found) > +{ > + u32 npkts_total = m->mux_buf_offset / TS_PACKET_LEN; > + u8 *buf = kcalloc(npkts_total, sizeof(u32), GFP_KERNEL); > + u32 npkt = 0; > + u32 pkt_offset = 0; > + u32 offset; > + u16 pkt_pid; > + > + for (offset = 0; offset < m->mux_buf_offset; offset += TS_PACKET_LEN) { > + pkt_pid = vidtv_ts_get_pid(&m->mux_buf[offset]); > + if (pkt_pid == pid) { > + buf[npkt] = offset; > + npkt++; > + } > + } > + > + *found = (npkt != 0); > + pkt_offset = buf[prandom_u32_max(npkt)]; > + kfree(buf); > + return pkt_offset; > +} Please create a drivers/media/test-drivers/vidtv/vidtv_debugfs.c file and place everything related to debugfs on it. At the header file, you would do: #if CONFIG_DVB_VIDTV_DEBUGFS u32 vidtv_mux_get_random_pkt_offset_for_pid(struct vidtv_mux *m, u16 pid, bool *found); #else static inline u32 vidtv_mux_get_random_pkt_offset_for_pid(struct vidtv_mux *m, u16 pid, bool *found) { return 0; } #endif for all functions. This way, the C files will be cleaner, as there won't be any "#if" inside them, and the header files will declare function stubs that will do nothing, which causes the compiler to simply discard the entire function as a hole. > + > +static void vidtv_mux_handle_debugfs_input(struct vidtv_mux *m, u32 *nbytes) > +{ > + struct vidtv_mux_pid_ctx *ctx; > + u32 pkt_offset; > + u16 pid; > + int bkt; > + bool found; > + u32 offset; > + > +#ifndef CONFIG_DVB_VIDTV_DEBUGFS > + return; > +#endif //CONFIG_DVB_VIDTV_DEBUGFS Never do that! if compiled without CONFIG_DVB_VIDTV_DEBUGFS, there will be dead code at the function. > + > + if (m->mux_buf_offset == 0) > + return; > + > + while (m->debugfs.discontinuity > 0) { > + pkt_offset = vidtv_mux_get_random_pkt_offset(m); > + pid = vidtv_ts_get_pid(&m->mux_buf[pkt_offset]); > + vidtv_mux_discontinuity_random(m, 10000, pid); > + m->debugfs.discontinuity--; > + } > + > + while (m->debugfs.drop > 0) { > + pkt_offset = vidtv_mux_get_random_pkt_offset(m); > + vidtv_mux_drop_random(m, 10000, pkt_offset, nbytes); > + m->debugfs.drop--; > + } > + > + while (m->debugfs.shl > 0) { > + pkt_offset = vidtv_mux_get_random_pkt_offset(m); > + vidtv_mux_shl_random(m, 10000, pkt_offset); > + m->debugfs.shl--; > + } > + > + while (m->debugfs.shr > 0) { > + pkt_offset = vidtv_mux_get_random_pkt_offset(m); > + vidtv_mux_shr_random(m, 10000, pkt_offset); > + m->debugfs.shr--; > + } > + > + for (offset = 0; offset < m->mux_buf_offset; offset += TS_PACKET_LEN) { > + pid = vidtv_ts_get_pid(&m->mux_buf[offset]); > + vidtv_mux_discontinuity_random(m, m->debugfs.discontinuity_probability, pid); > + vidtv_mux_add_random_noise(m, m->debugfs.noise, offset); > + vidtv_mux_drop_random(m, m->debugfs.drop_probability, offset, nbytes); > + vidtv_mux_shl_random(m, m->debugfs.shl_probability, offset); > + vidtv_mux_shr_random(m, m->debugfs.shr_probability, offset); > + } > + > + hash_for_each(m->pid_ctx, bkt, ctx, h) { > + while (ctx->debugfs.discontinuity > 0) { > + pkt_offset = vidtv_mux_get_random_pkt_offset_for_pid(m, ctx->pid, &found); > + vidtv_mux_discontinuity_random(m, 10000, ctx->pid); > + ctx->debugfs.discontinuity--; > + } > + > + while (ctx->debugfs.drop > 0) { > + pkt_offset = vidtv_mux_get_random_pkt_offset_for_pid(m, ctx->pid, &found); > + if (found) > + vidtv_mux_drop_random(m, 10000, pkt_offset, nbytes); > + ctx->debugfs.drop--; > + } > + > + while (ctx->debugfs.shl > 0) { > + pkt_offset = vidtv_mux_get_random_pkt_offset_for_pid(m, ctx->pid, &found); > + if (found) > + vidtv_mux_shl_random(m, 10000, pkt_offset); > + ctx->debugfs.shl--; > + } > + > + while (ctx->debugfs.shr > 0) { > + pkt_offset = vidtv_mux_get_random_pkt_offset_for_pid(m, ctx->pid, &found); > + if (found) > + vidtv_mux_shr_random(m, 10000, pkt_offset); > + ctx->debugfs.shr--; > + } > + > + for (offset = 0; offset < m->mux_buf_offset; offset += TS_PACKET_LEN) { > + pid = vidtv_ts_get_pid(&m->mux_buf[offset]); > + if (ctx->pid == pid) { > + vidtv_mux_discontinuity_random(m, > + m->debugfs.discontinuity_probability, > + pid); > + vidtv_mux_add_random_noise(m, ctx->debugfs.noise, offset); > + vidtv_mux_drop_random(m, ctx->debugfs.drop_probability, > + offset, nbytes); > + vidtv_mux_shl_random(m, ctx->debugfs.shl_probability, offset); > + vidtv_mux_shr_random(m, ctx->debugfs.shr_probability, offset); > + } > + } > + } > +} > + > #define ERR_RATE 10000000 > static void vidtv_mux_tick(struct work_struct *work) > { > @@ -410,6 +611,7 @@ static void vidtv_mux_tick(struct work_struct *work) > nbytes += vidtv_mux_poll_encoders(m); > nbytes += vidtv_mux_pad_with_nulls(m, 256); > > + vidtv_mux_handle_debugfs_input(m, &nbytes); > npkts = nbytes / TS_PACKET_LEN; > > /* if the buffer is not aligned there is a bug somewhere */ > @@ -474,6 +676,71 @@ void vidtv_mux_stop_thread(struct vidtv_mux *m) > } > } > > +static void vidtv_mux_debugfs_init(struct vidtv_mux *m, struct dentry *parent) > +{ > + struct dentry *frontend_dir; > + struct dentry *pid_dir; > + struct vidtv_mux_pid_ctx *ctx; > + int bkt; > + char name[16]; > + struct dtv_frontend_properties *c; > + > +#ifndef CONFIG_DVB_VIDTV_DEBUGFS > + return; > +#endif //CONFIG_DVB_VIDTV_DEBUGFS Same above notes apply here: place it on a separate C file and don't keep dead code, using the inline void do-nothing functions at the header, if compiled without CONFIG_DVB_VIDTV_DEBUGFS. > + > + c = &m->fe->dtv_property_cache; > + //Change this if vidtv ever supports simulating more than one frontend > + frontend_dir = debugfs_create_dir("frontend0", parent); > + if (IS_ERR(frontend_dir)) > + return; > + > + debugfs_create_u64("pre_bit_count", 0444, frontend_dir, &c->pre_bit_count.stat[0].uvalue); > + debugfs_create_u64("post_bit_count", 0444, frontend_dir, &c->post_bit_count.stat[0].uvalue); > + debugfs_create_u64("block_count", 0444, frontend_dir, &c->block_count.stat[0].uvalue); > + > + /* these work at random for any PID in this mux */ > + debugfs_create_u32("noise", 0644, frontend_dir, &m->debugfs.noise); > + debugfs_create_u32("drop_probability", 0644, frontend_dir, &m->debugfs.drop_probability); > + debugfs_create_u32("shl_probability", 0644, frontend_dir, &m->debugfs.shl_probability); > + debugfs_create_u32("shr_probability", 0644, frontend_dir, &m->debugfs.shr_probability); > + debugfs_create_u32("discontinuity_probability", 0644, frontend_dir, > + &m->debugfs.discontinuity_probability); > + debugfs_create_u32("drop", 0644, frontend_dir, &m->debugfs.drop); > + debugfs_create_u32("shl", 0644, frontend_dir, &m->debugfs.shl); > + debugfs_create_u32("shr", 0644, frontend_dir, &m->debugfs.shr); > + debugfs_create_u32("discontinuity", 0644, frontend_dir, &m->debugfs.discontinuity); > + > + hash_for_each(m->pid_ctx, bkt, ctx, h) { > + memset(name, 0, ARRAY_SIZE(name)); > + snprintf(name, ARRAY_SIZE(name), "PID_%d", ctx->pid); > + > + pid_dir = debugfs_create_dir(name, frontend_dir); > + if (IS_ERR(pid_dir)) > + return; > + > + /* these will affect the chosen PID only */ > + debugfs_create_u32("noise", 0644, pid_dir, &ctx->debugfs.noise); > + debugfs_create_u32("drop_probability", 0644, pid_dir, > + &ctx->debugfs.drop_probability); > + debugfs_create_u32("shl_probability", 0644, pid_dir, > + &ctx->debugfs.shl_probability); > + debugfs_create_u32("shr_probability", 0644, pid_dir, > + &ctx->debugfs.shr_probability); > + debugfs_create_u32("discontinuity_probability", 0644, pid_dir, > + &ctx->debugfs.discontinuity_probability); > + debugfs_create_u32("drop", 0644, pid_dir, &ctx->debugfs.drop); > + debugfs_create_u32("shl", 0644, pid_dir, &ctx->debugfs.shl); > + debugfs_create_u32("shr", 0644, pid_dir, &ctx->debugfs.shr); > + debugfs_create_u32("discontinuity", 0644, pid_dir, > + &ctx->debugfs.discontinuity); > + > + ctx->debugfs.dir_dentry = pid_dir; > + } > + > + m->debugfs.dir_dentry = frontend_dir; > +} > + > struct vidtv_mux *vidtv_mux_init(struct dvb_frontend *fe, > struct device *dev, > struct vidtv_mux_init_args *args) > @@ -521,6 +788,8 @@ struct vidtv_mux *vidtv_mux_init(struct dvb_frontend *fe, > if (vidtv_mux_pid_ctx_init(m) < 0) > goto free_channel_si; > > + vidtv_mux_debugfs_init(m, args->debugfs_root); > + > return m; > > free_channel_si: > @@ -542,5 +811,8 @@ void vidtv_mux_destroy(struct vidtv_mux *m) > vidtv_channels_destroy(m); > kfree(m->network_name); > vfree(m->mux_buf); > +#ifdef CONFIG_DVB_VIDTV_DEBUGFS > + debugfs_remove_recursive(m->debugfs.dir_dentry); > +#endif //CONFIG_DVB_VIDTV_DEBUGFS Instead, please do something like this at the .h file: #ifdef CONFIG_DVB_VIDTV_DEBUGFS ... vidtv_mux_debugfs_remove(...) { debugfs_remove_recursive(m->debugfs.dir_dentry); } ... #else ... static inline vidtv_mux_debugfs_remove(...) {} ... #endif and just call it unconditionally here. > kfree(m); > } > diff --git a/drivers/media/test-drivers/vidtv/vidtv_mux.h b/drivers/media/test-drivers/vidtv/vidtv_mux.h > index ad82eb72b841..b6ca9f330afd 100644 > --- a/drivers/media/test-drivers/vidtv/vidtv_mux.h > +++ b/drivers/media/test-drivers/vidtv/vidtv_mux.h > @@ -22,6 +22,7 @@ > #include <media/dvb_frontend.h> > > #include "vidtv_psi.h" > +#include "vidtv_debugfs.h" > > /** > * struct vidtv_mux_timing - Timing related information > @@ -77,11 +78,13 @@ struct vidtv_mux_si { > * @cc: The continuity counter for this PID. It is incremented on every TS > * pack and it will wrap around at 0xf0. If the decoder notices a sudden jump in > * this counter this will trigger a discontinuity state. > + * @debugfs: debugfs interface for this mpeg pid > * @h: This is embedded in a hash table, mapping pid -> vidtv_mux_pid_ctx > */ > struct vidtv_mux_pid_ctx { > u16 pid; > u8 cc; /* continuity counter */ > + struct vidtv_debugfs debugfs; > struct hlist_node h; > }; > > @@ -108,6 +111,7 @@ struct vidtv_mux_pid_ctx { > * @transport_stream_id: The transport stream ID > * @network_id: The network ID > * @network_name: The network name > + * @debugfs: The debugfs interface for the whole mux, if any. > * @priv: Private data. > */ > struct vidtv_mux { > @@ -139,6 +143,7 @@ struct vidtv_mux { > u16 transport_stream_id; > u16 network_id; > char *network_name; > + struct vidtv_debugfs debugfs; > void *priv; > }; > > @@ -155,6 +160,7 @@ struct vidtv_mux { > * @channels: an optional list of channels to use > * @network_id: The network ID > * @network_name: The network name > + * @debugfs_root: the debugfs root directory, if any > * @priv: Private data. > */ > struct vidtv_mux_init_args { > @@ -168,6 +174,7 @@ struct vidtv_mux_init_args { > struct vidtv_channel *channels; > u16 network_id; > char *network_name; > + struct dentry *debugfs_root; > void *priv; > }; > > diff --git a/drivers/media/test-drivers/vidtv/vidtv_ts.c b/drivers/media/test-drivers/vidtv/vidtv_ts.c > index ca4bb9c40b78..dca6fa8afa57 100644 > --- a/drivers/media/test-drivers/vidtv/vidtv_ts.c > +++ b/drivers/media/test-drivers/vidtv/vidtv_ts.c > @@ -134,3 +134,11 @@ u32 vidtv_ts_pcr_write_into(struct pcr_write_args args) > > return nbytes; > } > + > +u16 vidtv_ts_get_pid(u8 *pkt) > +{ > + struct vidtv_mpeg_ts *ts_pkt = (struct vidtv_mpeg_ts *)pkt; > + u16 bitfield = be16_to_cpu(ts_pkt->bitfield); > + u16 ret = bitfield & GENMASK(12, 0); > + return ret; > +} > diff --git a/drivers/media/test-drivers/vidtv/vidtv_ts.h b/drivers/media/test-drivers/vidtv/vidtv_ts.h > index 09b4ffd02829..f19824021966 100644 > --- a/drivers/media/test-drivers/vidtv/vidtv_ts.h > +++ b/drivers/media/test-drivers/vidtv/vidtv_ts.h > @@ -103,4 +103,12 @@ u32 vidtv_ts_null_write_into(struct null_packet_write_args args); > */ > u32 vidtv_ts_pcr_write_into(struct pcr_write_args args); > > +/** > + * vidtv_ts_get_pid - Extract the MPEG PID value out of a mpeg ts packet > + * @pkt: pointer to packet > + * > + * Return: The mpeg ts pid in cpu endianness > + */ > +u16 vidtv_ts_get_pid(u8 *pkt); > + > #endif //VIDTV_TS_H Thanks, Mauro
Hi Mauro! Thanks for the review. Just one more thing though: what did you think about the way I chose to inject the errors? (e.g. drop packet, shift bytes, create discontinuity...etc etc) I was just trying out a few ideas in this patch so if you also have any input on this please let me know. As of now writing to any of these files will cause a myriad of errors on dvbinspector. >> + >> +#. dynamically inject errors at runtime by interacting with the files at /sys/kernel/debug/vidtv/* >> + >> +#. read some dvbv5 statistics from userspace more easily >> + >> +.. note:: >> + This is entirely optional and the driver will work without this option selected. > Please keep lines <= 80 columns, except when there's a strong reason to > use longer lines. The same applies to other parts of this patch. > I was under the assumption that this had been bumped to 100 recently. -- thanks -- Daniel
diff --git a/Documentation/driver-api/media/drivers/vidtv.rst b/Documentation/driver-api/media/drivers/vidtv.rst index 673bdff919ea..e7c450289774 100644 --- a/Documentation/driver-api/media/drivers/vidtv.rst +++ b/Documentation/driver-api/media/drivers/vidtv.rst @@ -227,6 +227,9 @@ vidtv_mux.[ch] #. Delivering the resulting TS packets to the bridge driver so it can pass them to the demux. +vidtv_debugfs.h + Exposes data structures used in vidtv's debugfs interface. + Testing vidtv with v4l-utils ---------------------------- @@ -431,27 +434,53 @@ For more information on dvb-zap check its online documentation here: See also: `zap <https://www.linuxtv.org/wiki/index.php/Zap>`_. -What can still be improved in vidtv ------------------------------------ +Vidtv *debugfs* integration +___________________________ + +Vidtv now comes with a *debugfs* interface that can be enabled by selecting +**DVB_VIDTV_DEBUGFS**. Using it, one can + +#. dynamically inject errors at runtime by interacting with the files at /sys/kernel/debug/vidtv/* + +#. read some dvbv5 statistics from userspace more easily + +.. note:: + This is entirely optional and the driver will work without this option selected. + +At boot, vidtv will set up a directory per simulated frontend. Here is a list of +created files and their associated functionality once they are written to: + +noise + The probability of adding random noise in the packets (0 - 10000). +drop + Drop n packets at random +shl + Shift left n bytes at random +shr + Shift right n bytes at random +discontinuity + Create n discontinuities at random. This means artificially increasing + the continuity counters such that a discontinuity error is generated. + +Another option is to provide a probability of such events ocurring. Drop, shl, +shr, and discontinuity have versions that take in a probability in the [0, +10000] range. -Add *debugfs* integration -~~~~~~~~~~~~~~~~~~~~~~~~~ +Writing to the files at the frontend directory will target all packets in the +mux buffer. Alternatively, vidtv will also create a directory per PID. Writing +to these files will, in turn, only affect that particular PID. -Although frontend drivers provide DVBv5 statistics via the .read_status -call, a nice addition would be to make additional statistics available to -userspace via debugfs, which is a simple-to-use, RAM-based filesystem -specifically designed for debug purposes. -The logic for this would be implemented on a separate file so as not to -pollute the frontend driver. These statistics are driver-specific and can -be useful during tests. +What can still be improved in vidtv +----------------------------------- + +Improve debugfs support +~~~~~~~~~~~~~~~~~~~~~~~ -The Siano driver is one example of a driver using -debugfs to convey driver-specific statistics to userspace and it can be -used as a reference. +Vidtv offers support for dynamically injecting errors and retrieving some dvbv5 +stats via *debugfs*. This can be improved upon to add new ways of testing from +userspace. -This should be further enabled and disabled via a Kconfig -option for convenience. Add a way to test video ~~~~~~~~~~~~~~~~~~~~~~~ @@ -468,23 +497,6 @@ which resides at:: drivers/media/common/v4l2-tpg/ -Add white noise simulation -~~~~~~~~~~~~~~~~~~~~~~~~~~ - -The vidtv tuner already has code to identify whether the chosen frequency -is too far away from a table of valid frequencies. For now, this means that -the demodulator can eventually lose the lock on the signal, since the tuner will -report a bad signal quality. - -A nice addition is to simulate some noise when the signal quality is bad by: - -- Randomly dropping some TS packets. This will trigger a continuity error if the - continuity counter is updated but the packet is not passed on to the demux. - -- Updating the error statistics accordingly (e.g. BER, etc). - -- Simulating some noise in the encoded data. - Functions and structs used within vidtv --------------------------------------- @@ -511,3 +523,5 @@ Functions and structs used within vidtv .. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_common.c .. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_tuner.c + +.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_debugfs.h diff --git a/drivers/media/test-drivers/vidtv/Kconfig b/drivers/media/test-drivers/vidtv/Kconfig index 22c4fd39461f..05513f1c67e1 100644 --- a/drivers/media/test-drivers/vidtv/Kconfig +++ b/drivers/media/test-drivers/vidtv/Kconfig @@ -8,4 +8,17 @@ config DVB_VIDTV working on userspace applications. + When in doubt, say N. + +config DVB_VIDTV_DEBUGFS + bool "Enable debugfs for vidtv" + depends on DVB_VIDTV + depends on DEBUG_FS + + help + Choose Y to enable the vidtv debugfs interface. Currently allows for + dynamically introducing errors in the generated MPEG Transport Stream + for testing purposes. + + When in doubt, say N. diff --git a/drivers/media/test-drivers/vidtv/vidtv_bridge.c b/drivers/media/test-drivers/vidtv/vidtv_bridge.c index fc64d0c8492a..d5ebe680724f 100644 --- a/drivers/media/test-drivers/vidtv/vidtv_bridge.c +++ b/drivers/media/test-drivers/vidtv/vidtv_bridge.c @@ -10,6 +10,7 @@ * Copyright (C) 2020 Daniel W. S. Almeida */ +#include <linux/debugfs.h> #include <linux/dev_printk.h> #include <linux/moduleparam.h> #include <linux/mutex.h> @@ -172,6 +173,7 @@ static int vidtv_start_streaming(struct vidtv_dvb *dvb) .transport_stream_id = VIDTV_DEFAULT_TS_ID, .network_id = VIDTV_DEFAULT_NETWORK_ID, .network_name = VIDTV_DEFAULT_NETWORK_NAME, + .debugfs_root = dvb->debugfs_root, .priv = dvb, }; struct device *dev = &dvb->pdev->dev; @@ -485,6 +487,7 @@ static int vidtv_bridge_dvb_init(struct vidtv_dvb *dvb) static int vidtv_bridge_probe(struct platform_device *pdev) { struct vidtv_dvb *dvb; + struct dentry *debugfs_root; int ret; dvb = kzalloc(sizeof(*dvb), GFP_KERNEL); @@ -501,6 +504,12 @@ static int vidtv_bridge_probe(struct platform_device *pdev) platform_set_drvdata(pdev, dvb); +#ifdef CONFIG_DVB_VIDTV_DEBUGFS + debugfs_root = debugfs_create_dir("vidtv", NULL); + if (!IS_ERR(debugfs_root)) + dvb->debugfs_root = debugfs_root; +#endif //CONFIG_DVB_VIDTV_DEBUGFS + dev_info(&pdev->dev, "Successfully initialized vidtv!\n"); return ret; @@ -516,6 +525,10 @@ static int vidtv_bridge_remove(struct platform_device *pdev) dvb = platform_get_drvdata(pdev); +#ifdef CONFIG_DVB_VIDTV_DEBUGFS + debugfs_remove_recursive(dvb->debugfs_root); +#endif //CONFIG_DVB_VIDTV_DEBUGFS + mutex_destroy(&dvb->feed_lock); for (i = 0; i < NUM_FE; ++i) { diff --git a/drivers/media/test-drivers/vidtv/vidtv_bridge.h b/drivers/media/test-drivers/vidtv/vidtv_bridge.h index 2528adaee27d..9ef37d8ad2cc 100644 --- a/drivers/media/test-drivers/vidtv/vidtv_bridge.h +++ b/drivers/media/test-drivers/vidtv/vidtv_bridge.h @@ -42,6 +42,7 @@ * @feed_lock: Protects access to the start/stop stream logic/data. * @streaming: Whether we are streaming now. * @mux: The abstraction responsible for delivering MPEG TS packets to the bridge. + * @debugfs_root: A handle to vidtv's debugfs directory */ struct vidtv_dvb { struct platform_device *pdev; @@ -60,6 +61,7 @@ struct vidtv_dvb { bool streaming; struct vidtv_mux *mux; + struct dentry *debugfs_root; }; #endif // VIDTV_BRIDG_H diff --git a/drivers/media/test-drivers/vidtv/vidtv_debugfs.h b/drivers/media/test-drivers/vidtv/vidtv_debugfs.h new file mode 100644 index 000000000000..1743fe6d96cf --- /dev/null +++ b/drivers/media/test-drivers/vidtv/vidtv_debugfs.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Vidtv serves as a reference DVB driver and helps validate the existing APIs + * in the media subsystem. It can also aid developers working on userspace + * applications. + * + * Copyright (C) 2020 Daniel W. S. Almeida + */ + +#ifndef VIDTV_DEBUGFS_H +#define VIDTV_DEBUGFS_H +#include <linux/debugfs.h> + +/** + * struct vidtv_debugfs - Represents the vidtv debugfs interface + * + * @dir_dentry: A handle to the debugfs dentry + * @noise: Probability of adding noise to a byte in a packet [0, 10000] + * @drop: Drop n packets at random. + * @drop_probability: Probability to randomly drop a packet [0, 10000] + * @shl_probability: Probability to randomly shift left a byte in a packet [0, 10000] + * @shr_probability: Probability to randomly shift right a byte in a packet [0, 10000] + * @discontinuity_probability: Probability of artificially creating a + * discontinuity error [0, 10000] + * @shl: Shift n bytes left at random, i.e. byte[i] = byte[i] << 1; + * @shr: Shift n bytes right at random, i.e. byte[i] = byte[i] >>1; + * @discontinuity: Create n discontinuity errors + */ +struct vidtv_debugfs { + struct dentry *dir_dentry; + u32 noise; + u32 drop_probability; + u32 shl_probability; + u32 shr_probability; + u32 discontinuity_probability; + u32 drop; + u32 shl; + u32 shr; + u32 discontinuity; +}; + +#endif //VIDTV_DEBUGFS_H diff --git a/drivers/media/test-drivers/vidtv/vidtv_mux.c b/drivers/media/test-drivers/vidtv/vidtv_mux.c index b51e6a3b8cbe..e6d69fe01908 100644 --- a/drivers/media/test-drivers/vidtv/vidtv_mux.c +++ b/drivers/media/test-drivers/vidtv/vidtv_mux.c @@ -12,11 +12,14 @@ * Copyright (C) 2020 Daniel W. S. Almeida */ +#include "vidtv_debugfs.h" +#include <linux/debugfs.h> #include <linux/delay.h> #include <linux/dev_printk.h> #include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/math64.h> +#include <linux/random.h> #include <linux/ratelimit.h> #include <linux/slab.h> #include <linux/types.h> @@ -385,6 +388,204 @@ static void vidtv_mux_clear(struct vidtv_mux *m) m->mux_buf_offset = 0; } +static void vidtv_mux_add_random_noise(struct vidtv_mux *m, u32 noise_prob, u32 pkt_start) +{ + u8 noise; + u8 *pkt = m->mux_buf + pkt_start; + u32 i; + + for (i = 0; i < TS_PACKET_LEN; i++) + if (prandom_u32_max(10000) < noise_prob) { + noise = prandom_u32_max(0xff); + pkt[i] = pkt[i] + noise; + } +} + +static void vidtv_mux_drop_random(struct vidtv_mux *m, u32 drop_prob, u32 pkt_start, u32 *nbytes) +{ + u8 *pkt = m->mux_buf + pkt_start; + u8 *last_pkt = m->mux_buf + m->mux_buf_offset - TS_PACKET_LEN; + u32 npkts = m->mux_buf_offset / 188; + + if (!npkts) + return; + + if (prandom_u32_max(10000) < drop_prob) { + if (npkts > 1 && pkt != last_pkt) { + //overwrite victim with last packet + memcpy(pkt, last_pkt, TS_PACKET_LEN); + //remove last packet from buffer + memset(last_pkt, 0, TS_PACKET_LEN); + } else { + //just erase it + memset(pkt, 0, TS_PACKET_LEN); + } + + //keep track of the loss of this packet + m->mux_buf_offset -= TS_PACKET_LEN; + *nbytes -= TS_PACKET_LEN; + } +} + +static void vidtv_mux_shl_random(struct vidtv_mux *m, u32 shl_prob, u32 pkt_start) +{ + u8 *pkt = m->mux_buf + pkt_start; + /* select one of the 188 bytes at random */ + u8 *byte = pkt + prandom_u32_max(TS_PACKET_LEN); + + if (prandom_u32_max(10000) < shl_prob) + *byte = *byte << 1; +} + +static void vidtv_mux_shr_random(struct vidtv_mux *m, u32 shr_prob, u32 pkt_start) +{ + u8 *pkt = m->mux_buf + pkt_start; + /* select one of the 188 bytes at random */ + u8 *byte = pkt + prandom_u32_max(TS_PACKET_LEN); + + if (prandom_u32_max(10000) < shr_prob) + *byte = *byte >> 1; +} + +static void vidtv_mux_discontinuity_random(struct vidtv_mux *m, u32 disc_prob, u16 pid) +{ + struct vidtv_mux_pid_ctx *ctx = vidtv_mux_get_pid_ctx(m, pid); + + /* if the pkt was previously corrupted such that we cannot retrieve its pid context + * anymore, then bail + */ + if (!ctx) + return; + + if (prandom_u32_max(10000) < disc_prob) + vidtv_ts_inc_cc(&ctx->cc); +} + +static u32 vidtv_mux_get_random_pkt_offset(struct vidtv_mux *m) +{ + u32 npkts = m->mux_buf_offset / TS_PACKET_LEN; + u32 pkt_offset = prandom_u32_max(npkts) * TS_PACKET_LEN; + + return pkt_offset; +} + +static u32 vidtv_mux_get_random_pkt_offset_for_pid(struct vidtv_mux *m, u16 pid, bool *found) +{ + u32 npkts_total = m->mux_buf_offset / TS_PACKET_LEN; + u8 *buf = kcalloc(npkts_total, sizeof(u32), GFP_KERNEL); + u32 npkt = 0; + u32 pkt_offset = 0; + u32 offset; + u16 pkt_pid; + + for (offset = 0; offset < m->mux_buf_offset; offset += TS_PACKET_LEN) { + pkt_pid = vidtv_ts_get_pid(&m->mux_buf[offset]); + if (pkt_pid == pid) { + buf[npkt] = offset; + npkt++; + } + } + + *found = (npkt != 0); + pkt_offset = buf[prandom_u32_max(npkt)]; + kfree(buf); + return pkt_offset; +} + +static void vidtv_mux_handle_debugfs_input(struct vidtv_mux *m, u32 *nbytes) +{ + struct vidtv_mux_pid_ctx *ctx; + u32 pkt_offset; + u16 pid; + int bkt; + bool found; + u32 offset; + +#ifndef CONFIG_DVB_VIDTV_DEBUGFS + return; +#endif //CONFIG_DVB_VIDTV_DEBUGFS + + if (m->mux_buf_offset == 0) + return; + + while (m->debugfs.discontinuity > 0) { + pkt_offset = vidtv_mux_get_random_pkt_offset(m); + pid = vidtv_ts_get_pid(&m->mux_buf[pkt_offset]); + vidtv_mux_discontinuity_random(m, 10000, pid); + m->debugfs.discontinuity--; + } + + while (m->debugfs.drop > 0) { + pkt_offset = vidtv_mux_get_random_pkt_offset(m); + vidtv_mux_drop_random(m, 10000, pkt_offset, nbytes); + m->debugfs.drop--; + } + + while (m->debugfs.shl > 0) { + pkt_offset = vidtv_mux_get_random_pkt_offset(m); + vidtv_mux_shl_random(m, 10000, pkt_offset); + m->debugfs.shl--; + } + + while (m->debugfs.shr > 0) { + pkt_offset = vidtv_mux_get_random_pkt_offset(m); + vidtv_mux_shr_random(m, 10000, pkt_offset); + m->debugfs.shr--; + } + + for (offset = 0; offset < m->mux_buf_offset; offset += TS_PACKET_LEN) { + pid = vidtv_ts_get_pid(&m->mux_buf[offset]); + vidtv_mux_discontinuity_random(m, m->debugfs.discontinuity_probability, pid); + vidtv_mux_add_random_noise(m, m->debugfs.noise, offset); + vidtv_mux_drop_random(m, m->debugfs.drop_probability, offset, nbytes); + vidtv_mux_shl_random(m, m->debugfs.shl_probability, offset); + vidtv_mux_shr_random(m, m->debugfs.shr_probability, offset); + } + + hash_for_each(m->pid_ctx, bkt, ctx, h) { + while (ctx->debugfs.discontinuity > 0) { + pkt_offset = vidtv_mux_get_random_pkt_offset_for_pid(m, ctx->pid, &found); + vidtv_mux_discontinuity_random(m, 10000, ctx->pid); + ctx->debugfs.discontinuity--; + } + + while (ctx->debugfs.drop > 0) { + pkt_offset = vidtv_mux_get_random_pkt_offset_for_pid(m, ctx->pid, &found); + if (found) + vidtv_mux_drop_random(m, 10000, pkt_offset, nbytes); + ctx->debugfs.drop--; + } + + while (ctx->debugfs.shl > 0) { + pkt_offset = vidtv_mux_get_random_pkt_offset_for_pid(m, ctx->pid, &found); + if (found) + vidtv_mux_shl_random(m, 10000, pkt_offset); + ctx->debugfs.shl--; + } + + while (ctx->debugfs.shr > 0) { + pkt_offset = vidtv_mux_get_random_pkt_offset_for_pid(m, ctx->pid, &found); + if (found) + vidtv_mux_shr_random(m, 10000, pkt_offset); + ctx->debugfs.shr--; + } + + for (offset = 0; offset < m->mux_buf_offset; offset += TS_PACKET_LEN) { + pid = vidtv_ts_get_pid(&m->mux_buf[offset]); + if (ctx->pid == pid) { + vidtv_mux_discontinuity_random(m, + m->debugfs.discontinuity_probability, + pid); + vidtv_mux_add_random_noise(m, ctx->debugfs.noise, offset); + vidtv_mux_drop_random(m, ctx->debugfs.drop_probability, + offset, nbytes); + vidtv_mux_shl_random(m, ctx->debugfs.shl_probability, offset); + vidtv_mux_shr_random(m, ctx->debugfs.shr_probability, offset); + } + } + } +} + #define ERR_RATE 10000000 static void vidtv_mux_tick(struct work_struct *work) { @@ -410,6 +611,7 @@ static void vidtv_mux_tick(struct work_struct *work) nbytes += vidtv_mux_poll_encoders(m); nbytes += vidtv_mux_pad_with_nulls(m, 256); + vidtv_mux_handle_debugfs_input(m, &nbytes); npkts = nbytes / TS_PACKET_LEN; /* if the buffer is not aligned there is a bug somewhere */ @@ -474,6 +676,71 @@ void vidtv_mux_stop_thread(struct vidtv_mux *m) } } +static void vidtv_mux_debugfs_init(struct vidtv_mux *m, struct dentry *parent) +{ + struct dentry *frontend_dir; + struct dentry *pid_dir; + struct vidtv_mux_pid_ctx *ctx; + int bkt; + char name[16]; + struct dtv_frontend_properties *c; + +#ifndef CONFIG_DVB_VIDTV_DEBUGFS + return; +#endif //CONFIG_DVB_VIDTV_DEBUGFS + + c = &m->fe->dtv_property_cache; + //Change this if vidtv ever supports simulating more than one frontend + frontend_dir = debugfs_create_dir("frontend0", parent); + if (IS_ERR(frontend_dir)) + return; + + debugfs_create_u64("pre_bit_count", 0444, frontend_dir, &c->pre_bit_count.stat[0].uvalue); + debugfs_create_u64("post_bit_count", 0444, frontend_dir, &c->post_bit_count.stat[0].uvalue); + debugfs_create_u64("block_count", 0444, frontend_dir, &c->block_count.stat[0].uvalue); + + /* these work at random for any PID in this mux */ + debugfs_create_u32("noise", 0644, frontend_dir, &m->debugfs.noise); + debugfs_create_u32("drop_probability", 0644, frontend_dir, &m->debugfs.drop_probability); + debugfs_create_u32("shl_probability", 0644, frontend_dir, &m->debugfs.shl_probability); + debugfs_create_u32("shr_probability", 0644, frontend_dir, &m->debugfs.shr_probability); + debugfs_create_u32("discontinuity_probability", 0644, frontend_dir, + &m->debugfs.discontinuity_probability); + debugfs_create_u32("drop", 0644, frontend_dir, &m->debugfs.drop); + debugfs_create_u32("shl", 0644, frontend_dir, &m->debugfs.shl); + debugfs_create_u32("shr", 0644, frontend_dir, &m->debugfs.shr); + debugfs_create_u32("discontinuity", 0644, frontend_dir, &m->debugfs.discontinuity); + + hash_for_each(m->pid_ctx, bkt, ctx, h) { + memset(name, 0, ARRAY_SIZE(name)); + snprintf(name, ARRAY_SIZE(name), "PID_%d", ctx->pid); + + pid_dir = debugfs_create_dir(name, frontend_dir); + if (IS_ERR(pid_dir)) + return; + + /* these will affect the chosen PID only */ + debugfs_create_u32("noise", 0644, pid_dir, &ctx->debugfs.noise); + debugfs_create_u32("drop_probability", 0644, pid_dir, + &ctx->debugfs.drop_probability); + debugfs_create_u32("shl_probability", 0644, pid_dir, + &ctx->debugfs.shl_probability); + debugfs_create_u32("shr_probability", 0644, pid_dir, + &ctx->debugfs.shr_probability); + debugfs_create_u32("discontinuity_probability", 0644, pid_dir, + &ctx->debugfs.discontinuity_probability); + debugfs_create_u32("drop", 0644, pid_dir, &ctx->debugfs.drop); + debugfs_create_u32("shl", 0644, pid_dir, &ctx->debugfs.shl); + debugfs_create_u32("shr", 0644, pid_dir, &ctx->debugfs.shr); + debugfs_create_u32("discontinuity", 0644, pid_dir, + &ctx->debugfs.discontinuity); + + ctx->debugfs.dir_dentry = pid_dir; + } + + m->debugfs.dir_dentry = frontend_dir; +} + struct vidtv_mux *vidtv_mux_init(struct dvb_frontend *fe, struct device *dev, struct vidtv_mux_init_args *args) @@ -521,6 +788,8 @@ struct vidtv_mux *vidtv_mux_init(struct dvb_frontend *fe, if (vidtv_mux_pid_ctx_init(m) < 0) goto free_channel_si; + vidtv_mux_debugfs_init(m, args->debugfs_root); + return m; free_channel_si: @@ -542,5 +811,8 @@ void vidtv_mux_destroy(struct vidtv_mux *m) vidtv_channels_destroy(m); kfree(m->network_name); vfree(m->mux_buf); +#ifdef CONFIG_DVB_VIDTV_DEBUGFS + debugfs_remove_recursive(m->debugfs.dir_dentry); +#endif //CONFIG_DVB_VIDTV_DEBUGFS kfree(m); } diff --git a/drivers/media/test-drivers/vidtv/vidtv_mux.h b/drivers/media/test-drivers/vidtv/vidtv_mux.h index ad82eb72b841..b6ca9f330afd 100644 --- a/drivers/media/test-drivers/vidtv/vidtv_mux.h +++ b/drivers/media/test-drivers/vidtv/vidtv_mux.h @@ -22,6 +22,7 @@ #include <media/dvb_frontend.h> #include "vidtv_psi.h" +#include "vidtv_debugfs.h" /** * struct vidtv_mux_timing - Timing related information @@ -77,11 +78,13 @@ struct vidtv_mux_si { * @cc: The continuity counter for this PID. It is incremented on every TS * pack and it will wrap around at 0xf0. If the decoder notices a sudden jump in * this counter this will trigger a discontinuity state. + * @debugfs: debugfs interface for this mpeg pid * @h: This is embedded in a hash table, mapping pid -> vidtv_mux_pid_ctx */ struct vidtv_mux_pid_ctx { u16 pid; u8 cc; /* continuity counter */ + struct vidtv_debugfs debugfs; struct hlist_node h; }; @@ -108,6 +111,7 @@ struct vidtv_mux_pid_ctx { * @transport_stream_id: The transport stream ID * @network_id: The network ID * @network_name: The network name + * @debugfs: The debugfs interface for the whole mux, if any. * @priv: Private data. */ struct vidtv_mux { @@ -139,6 +143,7 @@ struct vidtv_mux { u16 transport_stream_id; u16 network_id; char *network_name; + struct vidtv_debugfs debugfs; void *priv; }; @@ -155,6 +160,7 @@ struct vidtv_mux { * @channels: an optional list of channels to use * @network_id: The network ID * @network_name: The network name + * @debugfs_root: the debugfs root directory, if any * @priv: Private data. */ struct vidtv_mux_init_args { @@ -168,6 +174,7 @@ struct vidtv_mux_init_args { struct vidtv_channel *channels; u16 network_id; char *network_name; + struct dentry *debugfs_root; void *priv; }; diff --git a/drivers/media/test-drivers/vidtv/vidtv_ts.c b/drivers/media/test-drivers/vidtv/vidtv_ts.c index ca4bb9c40b78..dca6fa8afa57 100644 --- a/drivers/media/test-drivers/vidtv/vidtv_ts.c +++ b/drivers/media/test-drivers/vidtv/vidtv_ts.c @@ -134,3 +134,11 @@ u32 vidtv_ts_pcr_write_into(struct pcr_write_args args) return nbytes; } + +u16 vidtv_ts_get_pid(u8 *pkt) +{ + struct vidtv_mpeg_ts *ts_pkt = (struct vidtv_mpeg_ts *)pkt; + u16 bitfield = be16_to_cpu(ts_pkt->bitfield); + u16 ret = bitfield & GENMASK(12, 0); + return ret; +} diff --git a/drivers/media/test-drivers/vidtv/vidtv_ts.h b/drivers/media/test-drivers/vidtv/vidtv_ts.h index 09b4ffd02829..f19824021966 100644 --- a/drivers/media/test-drivers/vidtv/vidtv_ts.h +++ b/drivers/media/test-drivers/vidtv/vidtv_ts.h @@ -103,4 +103,12 @@ u32 vidtv_ts_null_write_into(struct null_packet_write_args args); */ u32 vidtv_ts_pcr_write_into(struct pcr_write_args args); +/** + * vidtv_ts_get_pid - Extract the MPEG PID value out of a mpeg ts packet + * @pkt: pointer to packet + * + * Return: The mpeg ts pid in cpu endianness + */ +u16 vidtv_ts_get_pid(u8 *pkt); + #endif //VIDTV_TS_H