| Message ID | 20210224055135.1509200-1-davidm@egauge.net |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/4] wilc1000: Make SPI transfers work at 48MHz | expand |
On 24/02/21 11:22 am, David Mosberger-Tang wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > The driver so far has always disabled CRC protection. This means any > data corruption that occurred during the SPI transfers could > potentially go unnoticed. This patch adds the macros ENABLE_CRC7 and > ENABLE_CRC16 to allow compile-time selection of whether or not CRC7 > and CRC16, respectively, should be enabled. > > The default configuration remains unchanged, with both CRC7 and CRC16 > off. > > Signed-off-by: David Mosberger-Tang <davidm@egauge.net> > --- > .../net/wireless/microchip/wilc1000/Kconfig | 1 + > drivers/net/wireless/microchip/wilc1000/spi.c | 151 +++++++++++++----- > 2 files changed, 108 insertions(+), 44 deletions(-) > > diff --git a/drivers/net/wireless/microchip/wilc1000/Kconfig b/drivers/net/wireless/microchip/wilc1000/Kconfig > index 7f15e42602dd..62cfcdc9aacc 100644 > --- a/drivers/net/wireless/microchip/wilc1000/Kconfig > +++ b/drivers/net/wireless/microchip/wilc1000/Kconfig > @@ -27,6 +27,7 @@ config WILC1000_SPI > depends on CFG80211 && INET && SPI > select WILC1000 > select CRC7 > + select CRC_ITU_T > help > This module adds support for the SPI interface of adapters using > WILC1000 chipset. The Atmel WILC1000 has a Serial Peripheral > diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wireless/microchip/wilc1000/spi.c > index b0e096a03a28..c745a440d273 100644 > --- a/drivers/net/wireless/microchip/wilc1000/spi.c > +++ b/drivers/net/wireless/microchip/wilc1000/spi.c > @@ -7,10 +7,23 @@ > #include <linux/clk.h> > #include <linux/spi/spi.h> > #include <linux/crc7.h> > +#include <linux/crc-itu-t.h> > > #include "netdev.h" > #include "cfg80211.h" > > +/** > + * Establish the driver's desired CRC configuration. CRC7 is used for > + * command transfers which have no other protection against corruption > + * during the SPI transfer. Commands are short so CRC7 is relatively > + * cheap. CRC16 is used for data transfers, including network packet > + * transfers. Since those transfers can be large, CRC16 is relatively > + * expensive. CRC16 is also often redundant as network packets > + * typically are protected by their own, higher-level checksum. > + */ > +#define ENABLE_CRC7 0 /* set to 1 to protect SPI commands with CRC7 */ > +#define ENABLE_CRC16 0 /* set to 1 to protect SPI data with CRC16 */ > + > /* > * For CMD_SINGLE_READ and CMD_INTERNAL_READ, WILC may insert one or > * more zero bytes between the command response and the DATA Start tag > @@ -22,7 +35,8 @@ > #define WILC_SPI_RSP_HDR_EXTRA_DATA 8 > > struct wilc_spi { > - int crc_off; > + bool crc7_enabled; > + bool crc16_enabled; > }; > > static const struct wilc_hif_func wilc_hif_spi; > @@ -123,6 +137,10 @@ static int wilc_bus_probe(struct spi_device *spi) > if (!spi_priv) > return -ENOMEM; > > + /* WILC chip resets to both CRCs enabled: */ > + spi_priv->crc7_enabled = true; > + spi_priv->crc16_enabled = true; > + > ret = wilc_cfg80211_init(&wilc, &spi->dev, WILC_HIF_SPI, &wilc_hif_spi); > if (ret) { > kfree(spi_priv); > @@ -303,7 +321,8 @@ static int spi_data_write(struct wilc *wilc, u8 *b, u32 sz) > struct wilc_spi *spi_priv = wilc->bus_data; > int ix, nbytes; > int result = 0; > - u8 cmd, order, crc[2] = {0}; > + u8 cmd, order, crc[2]; > + u16 crc_calc; > > /* > * Data > @@ -345,9 +364,12 @@ static int spi_data_write(struct wilc *wilc, u8 *b, u32 sz) > } > > /* > - * Write Crc > + * Write CRC > */ > - if (!spi_priv->crc_off) { > + if (spi_priv->crc16_enabled) { > + crc_calc = crc_itu_t(0xffff, &b[ix], nbytes); > + crc[0] = crc_calc >> 8; > + crc[1] = crc_calc; > if (wilc_spi_tx(wilc, crc, 2)) { > dev_err(&spi->dev, "Failed data block crc write, bus error...\n"); > result = -EINVAL; > @@ -381,11 +403,11 @@ static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b, > struct spi_device *spi = to_spi_device(wilc->dev); > struct wilc_spi *spi_priv = wilc->bus_data; > u8 wb[32], rb[32]; > - u8 crc[2]; > int cmd_len, resp_len, i; > + u16 crc_calc, crc_recv; > struct wilc_spi_cmd *c; > - struct wilc_spi_read_rsp_data *r_data; > struct wilc_spi_rsp_data *r; > + struct wilc_spi_read_rsp_data *r_data; > > memset(wb, 0x0, sizeof(wb)); > memset(rb, 0x0, sizeof(rb)); > @@ -409,7 +431,7 @@ static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b, > cmd_len = offsetof(struct wilc_spi_cmd, u.simple_cmd.crc); > resp_len = sizeof(*r) + sizeof(*r_data) + WILC_SPI_RSP_HDR_EXTRA_DATA; > > - if (!spi_priv->crc_off) { > + if (spi_priv->crc7_enabled) { > c->u.simple_cmd.crc[0] = wilc_get_crc7(wb, cmd_len); > cmd_len += 1; > resp_len += 2; > @@ -455,8 +477,16 @@ static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b, > if (b) > memcpy(b, r_data->data, 4); > > - if (!spi_priv->crc_off) > - memcpy(crc, r_data->crc, 2); > + if (!clockless && spi_priv->crc16_enabled) { > + crc_recv = (r_data->crc[0] << 8) | r_data->crc[1]; > + crc_calc = crc_itu_t(0xffff, r_data->data, 4); > + if (crc_recv != crc_calc) { > + dev_err(&spi->dev, "%s: bad CRC 0x%04x " > + "(calculated 0x%04x)\n", __func__, > + crc_recv, crc_calc); > + return -EINVAL; > + } > + } > > return 0; > } > @@ -483,7 +513,7 @@ static int wilc_spi_write_cmd(struct wilc *wilc, u8 cmd, u32 adr, u32 data, > c->u.internal_w_cmd.addr[1] = adr; > c->u.internal_w_cmd.data = cpu_to_be32(data); > cmd_len = offsetof(struct wilc_spi_cmd, u.internal_w_cmd.crc); > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > c->u.internal_w_cmd.crc[0] = wilc_get_crc7(wb, cmd_len); > } else if (cmd == CMD_SINGLE_WRITE) { > c->u.w_cmd.addr[0] = adr >> 16; > @@ -491,14 +521,14 @@ static int wilc_spi_write_cmd(struct wilc *wilc, u8 cmd, u32 adr, u32 data, > c->u.w_cmd.addr[2] = adr; > c->u.w_cmd.data = cpu_to_be32(data); > cmd_len = offsetof(struct wilc_spi_cmd, u.w_cmd.crc); > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > c->u.w_cmd.crc[0] = wilc_get_crc7(wb, cmd_len); > } else { > dev_err(&spi->dev, "write cmd [%x] not supported\n", cmd); > return -EINVAL; > } > > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > cmd_len += 1; > > resp_len = sizeof(*r); > @@ -536,6 +566,7 @@ static int wilc_spi_dma_rw(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz) > { > struct spi_device *spi = to_spi_device(wilc->dev); > struct wilc_spi *spi_priv = wilc->bus_data; > + u16 crc_recv, crc_calc; > u8 wb[32], rb[32]; > int cmd_len, resp_len; > int retry, ix = 0; > @@ -554,7 +585,7 @@ static int wilc_spi_dma_rw(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz) > c->u.dma_cmd.size[0] = sz >> 8; > c->u.dma_cmd.size[1] = sz; > cmd_len = offsetof(struct wilc_spi_cmd, u.dma_cmd.crc); > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > c->u.dma_cmd.crc[0] = wilc_get_crc7(wb, cmd_len); > } else if (cmd == CMD_DMA_EXT_WRITE || cmd == CMD_DMA_EXT_READ) { > c->u.dma_cmd_ext.addr[0] = adr >> 16; > @@ -564,14 +595,14 @@ static int wilc_spi_dma_rw(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz) > c->u.dma_cmd_ext.size[1] = sz >> 8; > c->u.dma_cmd_ext.size[2] = sz; > cmd_len = offsetof(struct wilc_spi_cmd, u.dma_cmd_ext.crc); > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > c->u.dma_cmd_ext.crc[0] = wilc_get_crc7(wb, cmd_len); > } else { > dev_err(&spi->dev, "dma read write cmd [%x] not supported\n", > cmd); > return -EINVAL; > } > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > cmd_len += 1; > > resp_len = sizeof(*r); > @@ -637,12 +668,35 @@ static int wilc_spi_dma_rw(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz) > } > > /* > - * Read Crc > + * Read CRC > */ > - if (!spi_priv->crc_off && wilc_spi_rx(wilc, crc, 2)) { > - dev_err(&spi->dev, > - "Failed block crc read, bus err\n"); > - return -EINVAL; > + if (spi_priv->crc16_enabled) { > + if (wilc_spi_rx(wilc, crc, 2)) { > + dev_err(&spi->dev, > + "Failed block crc read, bus err\n"); > + return -EINVAL; > + } > + crc_recv = (crc[0] << 8) | crc[1]; > + crc_calc = crc_itu_t(0xffff, &b[ix], nbytes); > + if (crc_recv != crc_calc) { > + dev_err(&spi->dev, "%s: bad CRC 0x%04x " > + "(calculated 0x%04x)\n", __func__, > + crc_recv, crc_calc); > + > + { > + u8 byte; > + int i; > + > + for (i = 0; i < 16384; ++i) { > + byte = 0; > + wilc_spi_rx(wilc, &byte, 1); > + if (!byte) > + break; > + } > + } > + > + return -EINVAL; > + } > } > > ix += nbytes; > @@ -871,43 +925,52 @@ static int wilc_spi_init(struct wilc *wilc, bool resume) > ret = spi_internal_read(wilc, WILC_SPI_PROTOCOL_OFFSET, ®); > if (ret) { > /* > - * Read failed. Try with CRC off. This might happen when module > - * is removed but chip isn't reset > + * Read failed. Try with CRC7 off. This might happen > + * when module is removed but chip isn't reset. > */ > - spi_priv->crc_off = 1; > + spi_priv->crc7_enabled = false; This patch series also looks okay to me. I just have one input which is captured below. We need to disable both crc7 and crc16 while retrying on failure attempt by adding below line spi_priv->crc16_enabled = false; By default the CRC checks are disabled, so if the kernel module is reloaded it should reattempt with both disabled. Regards Ajay > dev_err(&spi->dev, > - "Failed read with CRC on, retrying with CRC off\n"); > + "Failed read with CRC7 on, retrying with CRC7 off\n"); > ret = spi_internal_read(wilc, WILC_SPI_PROTOCOL_OFFSET, ®); > if (ret) { > /* > - * Read failed with both CRC on and off, > + * Read failed with both CRC7 on and off, > * something went bad > */ > dev_err(&spi->dev, "Failed internal read protocol\n"); > return ret; > } > } > - if (spi_priv->crc_off == 0) { > - /* disable crc checking: */ > - reg &= ~(PROTOCOL_REG_CRC7_MASK | PROTOCOL_REG_CRC16_MASK); > - > - /* set the data packet size: */ > - BUILD_BUG_ON(DATA_PKT_LOG_SZ < DATA_PKT_LOG_SZ_MIN > - || DATA_PKT_LOG_SZ > DATA_PKT_LOG_SZ_MAX); > - reg &= ~PROTOCOL_REG_PKT_SZ_MASK; > - reg |= FIELD_PREP(PROTOCOL_REG_PKT_SZ_MASK, > - DATA_PKT_LOG_SZ - DATA_PKT_LOG_SZ_MIN); > - > - ret = spi_internal_write(wilc, WILC_SPI_PROTOCOL_OFFSET, reg); > - if (ret) { > - dev_err(&spi->dev, > - "[wilc spi %d]: Failed internal write reg\n", > - __LINE__); > - return ret; > - } > - spi_priv->crc_off = 1; > + > + /* set up the desired CRC configuration: */ > + reg &= ~(PROTOCOL_REG_CRC7_MASK | PROTOCOL_REG_CRC16_MASK); > +#if ENABLE_CRC7 > + reg |= PROTOCOL_REG_CRC7_MASK; > +#endif > +#if ENABLE_CRC16 > + reg |= PROTOCOL_REG_CRC16_MASK; > +#endif > + > + /* set up the data packet size: */ > + BUILD_BUG_ON(DATA_PKT_LOG_SZ < DATA_PKT_LOG_SZ_MIN > + || DATA_PKT_LOG_SZ > DATA_PKT_LOG_SZ_MAX); > + reg &= ~PROTOCOL_REG_PKT_SZ_MASK; > + reg |= FIELD_PREP(PROTOCOL_REG_PKT_SZ_MASK, > + DATA_PKT_LOG_SZ - DATA_PKT_LOG_SZ_MIN); > + > + /* establish the new setup: */ > + ret = spi_internal_write(wilc, WILC_SPI_PROTOCOL_OFFSET, reg); > + if (ret) { > + dev_err(&spi->dev, > + "[wilc spi %d]: Failed internal write reg\n", > + __LINE__); > + return ret; > } > > + /* now that new set up is established, update our state to match: */ > + spi_priv->crc7_enabled = ENABLE_CRC7; > + spi_priv->crc16_enabled = ENABLE_CRC16; > + > /* > * make sure can read back chip id correctly > */ > -- > 2.25.1 >
On 24/02/21 11:22 am, David Mosberger-Tang wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > The driver so far has always disabled CRC protection. This means any > data corruption that occurred during the SPI transfers could > potentially go unnoticed. This patch adds the macros ENABLE_CRC7 and > ENABLE_CRC16 to allow compile-time selection of whether or not CRC7 > and CRC16, respectively, should be enabled. > > The default configuration remains unchanged, with both CRC7 and CRC16 > off. > > Signed-off-by: David Mosberger-Tang <davidm@egauge.net> > --- > .../net/wireless/microchip/wilc1000/Kconfig | 1 + > drivers/net/wireless/microchip/wilc1000/spi.c | 151 +++++++++++++----- > 2 files changed, 108 insertions(+), 44 deletions(-) > > diff --git a/drivers/net/wireless/microchip/wilc1000/Kconfig b/drivers/net/wireless/microchip/wilc1000/Kconfig > index 7f15e42602dd..62cfcdc9aacc 100644 > --- a/drivers/net/wireless/microchip/wilc1000/Kconfig > +++ b/drivers/net/wireless/microchip/wilc1000/Kconfig > @@ -27,6 +27,7 @@ config WILC1000_SPI > depends on CFG80211 && INET && SPI > select WILC1000 > select CRC7 > + select CRC_ITU_T > help > This module adds support for the SPI interface of adapters using > WILC1000 chipset. The Atmel WILC1000 has a Serial Peripheral > diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wireless/microchip/wilc1000/spi.c > index b0e096a03a28..c745a440d273 100644 > --- a/drivers/net/wireless/microchip/wilc1000/spi.c > +++ b/drivers/net/wireless/microchip/wilc1000/spi.c > @@ -7,10 +7,23 @@ > #include <linux/clk.h> > #include <linux/spi/spi.h> > #include <linux/crc7.h> > +#include <linux/crc-itu-t.h> > > #include "netdev.h" > #include "cfg80211.h" > > +/** > + * Establish the driver's desired CRC configuration. CRC7 is used for > + * command transfers which have no other protection against corruption > + * during the SPI transfer. Commands are short so CRC7 is relatively > + * cheap. CRC16 is used for data transfers, including network packet > + * transfers. Since those transfers can be large, CRC16 is relatively > + * expensive. CRC16 is also often redundant as network packets > + * typically are protected by their own, higher-level checksum. > + */ > +#define ENABLE_CRC7 0 /* set to 1 to protect SPI commands with CRC7 */ > +#define ENABLE_CRC16 0 /* set to 1 to protect SPI data with CRC16 */ > + > /* > * For CMD_SINGLE_READ and CMD_INTERNAL_READ, WILC may insert one or > * more zero bytes between the command response and the DATA Start tag > @@ -22,7 +35,8 @@ > #define WILC_SPI_RSP_HDR_EXTRA_DATA 8 > > struct wilc_spi { > - int crc_off; > + bool crc7_enabled; > + bool crc16_enabled; > }; > > static const struct wilc_hif_func wilc_hif_spi; > @@ -123,6 +137,10 @@ static int wilc_bus_probe(struct spi_device *spi) > if (!spi_priv) > return -ENOMEM; > > + /* WILC chip resets to both CRCs enabled: */ > + spi_priv->crc7_enabled = true; > + spi_priv->crc16_enabled = true; > + > ret = wilc_cfg80211_init(&wilc, &spi->dev, WILC_HIF_SPI, &wilc_hif_spi); > if (ret) { > kfree(spi_priv); > @@ -303,7 +321,8 @@ static int spi_data_write(struct wilc *wilc, u8 *b, u32 sz) > struct wilc_spi *spi_priv = wilc->bus_data; > int ix, nbytes; > int result = 0; > - u8 cmd, order, crc[2] = {0}; > + u8 cmd, order, crc[2]; > + u16 crc_calc; > > /* > * Data > @@ -345,9 +364,12 @@ static int spi_data_write(struct wilc *wilc, u8 *b, u32 sz) > } > > /* > - * Write Crc > + * Write CRC > */ > - if (!spi_priv->crc_off) { > + if (spi_priv->crc16_enabled) { > + crc_calc = crc_itu_t(0xffff, &b[ix], nbytes); > + crc[0] = crc_calc >> 8; > + crc[1] = crc_calc; > if (wilc_spi_tx(wilc, crc, 2)) { > dev_err(&spi->dev, "Failed data block crc write, bus error...\n"); > result = -EINVAL; > @@ -381,11 +403,11 @@ static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b, > struct spi_device *spi = to_spi_device(wilc->dev); > struct wilc_spi *spi_priv = wilc->bus_data; > u8 wb[32], rb[32]; > - u8 crc[2]; > int cmd_len, resp_len, i; > + u16 crc_calc, crc_recv; > struct wilc_spi_cmd *c; > - struct wilc_spi_read_rsp_data *r_data; > struct wilc_spi_rsp_data *r; > + struct wilc_spi_read_rsp_data *r_data; > > memset(wb, 0x0, sizeof(wb)); > memset(rb, 0x0, sizeof(rb)); > @@ -409,7 +431,7 @@ static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b, > cmd_len = offsetof(struct wilc_spi_cmd, u.simple_cmd.crc); > resp_len = sizeof(*r) + sizeof(*r_data) + WILC_SPI_RSP_HDR_EXTRA_DATA; > > - if (!spi_priv->crc_off) { > + if (spi_priv->crc7_enabled) { > c->u.simple_cmd.crc[0] = wilc_get_crc7(wb, cmd_len); > cmd_len += 1; > resp_len += 2; > @@ -455,8 +477,16 @@ static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b, > if (b) > memcpy(b, r_data->data, 4); > > - if (!spi_priv->crc_off) > - memcpy(crc, r_data->crc, 2); > + if (!clockless && spi_priv->crc16_enabled) { > + crc_recv = (r_data->crc[0] << 8) | r_data->crc[1]; > + crc_calc = crc_itu_t(0xffff, r_data->data, 4); > + if (crc_recv != crc_calc) { > + dev_err(&spi->dev, "%s: bad CRC 0x%04x " > + "(calculated 0x%04x)\n", __func__, > + crc_recv, crc_calc); > + return -EINVAL; > + } > + } > > return 0; > } > @@ -483,7 +513,7 @@ static int wilc_spi_write_cmd(struct wilc *wilc, u8 cmd, u32 adr, u32 data, > c->u.internal_w_cmd.addr[1] = adr; > c->u.internal_w_cmd.data = cpu_to_be32(data); > cmd_len = offsetof(struct wilc_spi_cmd, u.internal_w_cmd.crc); > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > c->u.internal_w_cmd.crc[0] = wilc_get_crc7(wb, cmd_len); > } else if (cmd == CMD_SINGLE_WRITE) { > c->u.w_cmd.addr[0] = adr >> 16; > @@ -491,14 +521,14 @@ static int wilc_spi_write_cmd(struct wilc *wilc, u8 cmd, u32 adr, u32 data, > c->u.w_cmd.addr[2] = adr; > c->u.w_cmd.data = cpu_to_be32(data); > cmd_len = offsetof(struct wilc_spi_cmd, u.w_cmd.crc); > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > c->u.w_cmd.crc[0] = wilc_get_crc7(wb, cmd_len); > } else { > dev_err(&spi->dev, "write cmd [%x] not supported\n", cmd); > return -EINVAL; > } > > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > cmd_len += 1; > > resp_len = sizeof(*r); > @@ -536,6 +566,7 @@ static int wilc_spi_dma_rw(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz) > { > struct spi_device *spi = to_spi_device(wilc->dev); > struct wilc_spi *spi_priv = wilc->bus_data; > + u16 crc_recv, crc_calc; > u8 wb[32], rb[32]; > int cmd_len, resp_len; > int retry, ix = 0; > @@ -554,7 +585,7 @@ static int wilc_spi_dma_rw(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz) > c->u.dma_cmd.size[0] = sz >> 8; > c->u.dma_cmd.size[1] = sz; > cmd_len = offsetof(struct wilc_spi_cmd, u.dma_cmd.crc); > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > c->u.dma_cmd.crc[0] = wilc_get_crc7(wb, cmd_len); > } else if (cmd == CMD_DMA_EXT_WRITE || cmd == CMD_DMA_EXT_READ) { > c->u.dma_cmd_ext.addr[0] = adr >> 16; > @@ -564,14 +595,14 @@ static int wilc_spi_dma_rw(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz) > c->u.dma_cmd_ext.size[1] = sz >> 8; > c->u.dma_cmd_ext.size[2] = sz; > cmd_len = offsetof(struct wilc_spi_cmd, u.dma_cmd_ext.crc); > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > c->u.dma_cmd_ext.crc[0] = wilc_get_crc7(wb, cmd_len); > } else { > dev_err(&spi->dev, "dma read write cmd [%x] not supported\n", > cmd); > return -EINVAL; > } > - if (!spi_priv->crc_off) > + if (spi_priv->crc7_enabled) > cmd_len += 1; > > resp_len = sizeof(*r); > @@ -637,12 +668,35 @@ static int wilc_spi_dma_rw(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz) > } > > /* > - * Read Crc > + * Read CRC > */ > - if (!spi_priv->crc_off && wilc_spi_rx(wilc, crc, 2)) { > - dev_err(&spi->dev, > - "Failed block crc read, bus err\n"); > - return -EINVAL; > + if (spi_priv->crc16_enabled) { > + if (wilc_spi_rx(wilc, crc, 2)) { > + dev_err(&spi->dev, > + "Failed block crc read, bus err\n"); > + return -EINVAL; > + } > + crc_recv = (crc[0] << 8) | crc[1]; > + crc_calc = crc_itu_t(0xffff, &b[ix], nbytes); > + if (crc_recv != crc_calc) { > + dev_err(&spi->dev, "%s: bad CRC 0x%04x " > + "(calculated 0x%04x)\n", __func__, > + crc_recv, crc_calc); One more observation. I am not clear if the below block is really needed. Have you faced any issue here and did the below logic of skipping data helped to come out of it. Also checking the limit of 16384(2*8KB) byte looks odd when the max limit for data packet is around 8KB. Am I missing something here. > + > + { > + u8 byte; > + int i; > + > + for (i = 0; i < 16384; ++i) { > + byte = 0; > + wilc_spi_rx(wilc, &byte, 1); > + if (!byte) > + break; > + } > + } > + > + return -EINVAL; > + } > } > > ix += nbytes; > @@ -871,43 +925,52 @@ static int wilc_spi_init(struct wilc *wilc, bool resume) > ret = spi_internal_read(wilc, WILC_SPI_PROTOCOL_OFFSET, ®); > if (ret) { > /* > - * Read failed. Try with CRC off. This might happen when module > - * is removed but chip isn't reset > + * Read failed. Try with CRC7 off. This might happen > + * when module is removed but chip isn't reset. > */ > - spi_priv->crc_off = 1; > + spi_priv->crc7_enabled = false; > dev_err(&spi->dev, > - "Failed read with CRC on, retrying with CRC off\n"); > + "Failed read with CRC7 on, retrying with CRC7 off\n"); > ret = spi_internal_read(wilc, WILC_SPI_PROTOCOL_OFFSET, ®); > if (ret) { > /* > - * Read failed with both CRC on and off, > + * Read failed with both CRC7 on and off, > * something went bad > */ > dev_err(&spi->dev, "Failed internal read protocol\n"); > return ret; > } > } > - if (spi_priv->crc_off == 0) { > - /* disable crc checking: */ > - reg &= ~(PROTOCOL_REG_CRC7_MASK | PROTOCOL_REG_CRC16_MASK); > - > - /* set the data packet size: */ > - BUILD_BUG_ON(DATA_PKT_LOG_SZ < DATA_PKT_LOG_SZ_MIN > - || DATA_PKT_LOG_SZ > DATA_PKT_LOG_SZ_MAX); > - reg &= ~PROTOCOL_REG_PKT_SZ_MASK; > - reg |= FIELD_PREP(PROTOCOL_REG_PKT_SZ_MASK, > - DATA_PKT_LOG_SZ - DATA_PKT_LOG_SZ_MIN); > - > - ret = spi_internal_write(wilc, WILC_SPI_PROTOCOL_OFFSET, reg); > - if (ret) { > - dev_err(&spi->dev, > - "[wilc spi %d]: Failed internal write reg\n", > - __LINE__); > - return ret; > - } > - spi_priv->crc_off = 1; > + > + /* set up the desired CRC configuration: */ > + reg &= ~(PROTOCOL_REG_CRC7_MASK | PROTOCOL_REG_CRC16_MASK); > +#if ENABLE_CRC7 > + reg |= PROTOCOL_REG_CRC7_MASK; > +#endif > +#if ENABLE_CRC16 > + reg |= PROTOCOL_REG_CRC16_MASK; > +#endif > + > + /* set up the data packet size: */ > + BUILD_BUG_ON(DATA_PKT_LOG_SZ < DATA_PKT_LOG_SZ_MIN > + || DATA_PKT_LOG_SZ > DATA_PKT_LOG_SZ_MAX); > + reg &= ~PROTOCOL_REG_PKT_SZ_MASK; > + reg |= FIELD_PREP(PROTOCOL_REG_PKT_SZ_MASK, > + DATA_PKT_LOG_SZ - DATA_PKT_LOG_SZ_MIN); > + > + /* establish the new setup: */ > + ret = spi_internal_write(wilc, WILC_SPI_PROTOCOL_OFFSET, reg); > + if (ret) { > + dev_err(&spi->dev, > + "[wilc spi %d]: Failed internal write reg\n", > + __LINE__); > + return ret; > } > > + /* now that new set up is established, update our state to match: */ > + spi_priv->crc7_enabled = ENABLE_CRC7; > + spi_priv->crc16_enabled = ENABLE_CRC16; > + > /* > * make sure can read back chip id correctly > */ > -- > 2.25.1 >
Julian, On Thu, 2021-02-25 at 08:19 +1100, Julian Calaby wrote: > Hi David, > > On Wed, Feb 24, 2021 at 6:56 PM David Mosberger-Tang < > davidm@egauge.net> wrote: > > > > +#define ENABLE_CRC7 0 /* set to 1 to protect SPI commands > > with CRC7 */ > > +#define ENABLE_CRC16 0 /* set to 1 to protect SPI data > > with CRC16 */ > > Should these be Kconfig variables instead? I'd certainly like that. Ajay, would you be OK with that? --david
On 24/02/21 9:55 pm, David Mosberger-Tang wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > On Wed, 2021-02-24 at 10:01 +0000, Ajay.Kathat@microchip.com wrote: > >> This patch series also looks okay to me. I just have one input which is >> captured below. >> >> We need to disable both crc7 and crc16 while retrying on failure attempt >> by adding below line >> >> spi_priv->crc16_enabled = false; > > Ah, you're right. We can always probe with CRC16 off since the chip > returns valid register data regardless of whether crc16_enabled is > true or false. I'm thinking something like this: > > spi_priv->crc16_enabled = false; // ignore CRC16 during CRC- > detection > for (crc7 = 1; crc7 >= 0; --crc7) { Its better to first try with crc7 disable and then with enable because our default configuration has both disabled so it will return success immediatly on reattempt for default configuration. for (crc7 = 0; crc7 <= 1; ++crc7) { > spi_priv->crc7_enabled = crc7; > ret = spi_internal_read(wilc, WILC_SPI_PROTOCOL_OFFSET, > ®); > if (ret == 0) > break; > } > if (ret) { > dev_err(&spi->dev, "Failed with all possible CRC > settings.\n"); > return ret; > } > >> By default the CRC checks are disabled, so if the kernel module is >> reloaded it should reattempt with both disabled. > > Are you sure about that? My test devices resets into: > > PROTOCOL_REG = 0x2e > > which should be CRC7 and CRC16 on, right? The workaround was added for scenario when kernel module is loaded without CRC enabled in WILC1000 chip. The scenario was observed during the kernel module unload(rmmod) then reload(insmod/modprobe). Mostly the driver will read with CRC ON but if it fails then read attempt should be tried with CRC OFF. Regards, Ajay
Hi David, On 24/02/21 9:17 pm, David Mosberger-Tang wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > Ajay, > > On Wed, 2021-02-24 at 13:35 +0000, Ajay.Kathat@microchip.com wrote: >> >> One more observation. >> I am not clear if the below block is really needed. Have you faced any >> issue here and did the below logic of skipping data helped to come out >> of it. Also checking the limit of 16384(2*8KB) byte looks odd when the >> max limit for data packet is around 8KB. Am I missing something here. >> >>> + >>> + { >>> + u8 byte; >>> + int i; >>> + >>> + for (i = 0; i < 16384; ++i) { >>> + byte = 0; >>> + wilc_spi_rx(wilc, &byte, 1); >>> + if (!byte) >>> + break; >>> + } >>> + } > > Ouch, that's definitely not supposed to be there! It's left-over debug > code from when I was tracking down the power-save issue. Not sure how > I missed that. Thanks for catching it and being so gentle about it! > > How do I fix this best? Do I resend the entire patch series or is it > OK to create a V2 of just this last patch? > It's better to resubmit the complete patch series v2, as it would be convenient for Kalle to apply the patches in order. Regards, Ajay
On 25/02/21 5:06 am, David Mosberger-Tang wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > Julian, > > On Thu, 2021-02-25 at 08:19 +1100, Julian Calaby wrote: >> Hi David, >> >> On Wed, Feb 24, 2021 at 6:56 PM David Mosberger-Tang < >> davidm@egauge.net> wrote: >>> >>> +#define ENABLE_CRC7 0 /* set to 1 to protect SPI commands >>> with CRC7 */ >>> +#define ENABLE_CRC16 0 /* set to 1 to protect SPI data >>> with CRC16 */ >> >> Should these be Kconfig variables instead? > > I'd certainly like that. Ajay, would you be OK with that? > Yes, I am fine with the changes to move as Kconfig variable. Regards Ajay
<Ajay.Kathat@microchip.com> writes: > On 25/02/21 5:06 am, David Mosberger-Tang wrote: >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >> >> Julian, >> >> On Thu, 2021-02-25 at 08:19 +1100, Julian Calaby wrote: >>> Hi David, >>> >>> On Wed, Feb 24, 2021 at 6:56 PM David Mosberger-Tang < >>> davidm@egauge.net> wrote: >>>> >>>> +#define ENABLE_CRC7 0 /* set to 1 to protect SPI commands >>>> with CRC7 */ >>>> +#define ENABLE_CRC16 0 /* set to 1 to protect SPI data >>>> with CRC16 */ >>> >>> Should these be Kconfig variables instead? >> >> I'd certainly like that. Ajay, would you be OK with that? >> > > Yes, I am fine with the changes to move as Kconfig variable. Kconfig is not ideal for configuring functionality, something like a module parameter is usually better. But why not just enable CRC always? Why would the user need to disable this? -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
<Ajay.Kathat@microchip.com> writes: > Hi David, > > On 24/02/21 9:17 pm, David Mosberger-Tang wrote: >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >> >> Ajay, >> >> On Wed, 2021-02-24 at 13:35 +0000, Ajay.Kathat@microchip.com wrote: >>> >>> One more observation. >>> I am not clear if the below block is really needed. Have you faced any >>> issue here and did the below logic of skipping data helped to come out >>> of it. Also checking the limit of 16384(2*8KB) byte looks odd when the >>> max limit for data packet is around 8KB. Am I missing something here. >>> >>>> + >>>> + { >>>> + u8 byte; >>>> + int i; >>>> + >>>> + for (i = 0; i < 16384; ++i) { >>>> + byte = 0; >>>> + wilc_spi_rx(wilc, &byte, 1); >>>> + if (!byte) >>>> + break; >>>> + } >>>> + } >> >> Ouch, that's definitely not supposed to be there! It's left-over debug >> code from when I was tracking down the power-save issue. Not sure how >> I missed that. Thanks for catching it and being so gentle about it! >> >> How do I fix this best? Do I resend the entire patch series or is it >> OK to create a V2 of just this last patch? >> > > It's better to resubmit the complete patch series v2, as it would be > convenient for Kalle to apply the patches in order. Correct. This is also documented in the wiki, see the link below. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
On 25/02/21 1:52 pm, Kalle Valo wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > <Ajay.Kathat@microchip.com> writes: > >> On 25/02/21 5:06 am, David Mosberger-Tang wrote: >>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >>> >>> Julian, >>> >>> On Thu, 2021-02-25 at 08:19 +1100, Julian Calaby wrote: >>>> Hi David, >>>> >>>> On Wed, Feb 24, 2021 at 6:56 PM David Mosberger-Tang < >>>> davidm@egauge.net> wrote: >>>>> >>>>> +#define ENABLE_CRC7 0 /* set to 1 to protect SPI commands >>>>> with CRC7 */ >>>>> +#define ENABLE_CRC16 0 /* set to 1 to protect SPI data >>>>> with CRC16 */ >>>> >>>> Should these be Kconfig variables instead? >>> >>> I'd certainly like that. Ajay, would you be OK with that? >>> >> >> Yes, I am fine with the changes to move as Kconfig variable. > > Kconfig is not ideal for configuring functionality, something like a > module parameter is usually better. But why not just enable CRC always? > Why would the user need to disable this? As I know, the CRC check can be an time taking operation for each data packets and in turn, can have impact on throughput performance. Generally, it is recommended to keep this CRC configuration disabled. But someone is cautious can enable it on a need basis by knowing the possible reduction on throughput number. Regards, Ajay
<Ajay.Kathat@microchip.com> writes: > On 25/02/21 1:52 pm, Kalle Valo wrote: >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >> >> <Ajay.Kathat@microchip.com> writes: >> >>> On 25/02/21 5:06 am, David Mosberger-Tang wrote: >>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >>>> >>>> Julian, >>>> >>>> On Thu, 2021-02-25 at 08:19 +1100, Julian Calaby wrote: >>>>> Hi David, >>>>> >>>>> On Wed, Feb 24, 2021 at 6:56 PM David Mosberger-Tang < >>>>> davidm@egauge.net> wrote: >>>>>> >>>>>> +#define ENABLE_CRC7 0 /* set to 1 to protect SPI commands >>>>>> with CRC7 */ >>>>>> +#define ENABLE_CRC16 0 /* set to 1 to protect SPI data >>>>>> with CRC16 */ >>>>> >>>>> Should these be Kconfig variables instead? >>>> >>>> I'd certainly like that. Ajay, would you be OK with that? >>>> >>> >>> Yes, I am fine with the changes to move as Kconfig variable. >> >> Kconfig is not ideal for configuring functionality, something like a >> module parameter is usually better. But why not just enable CRC always? >> Why would the user need to disable this? > > As I know, the CRC check can be an time taking operation for each data > packets and in turn, can have impact on throughput performance. > Generally, it is recommended to keep this CRC configuration disabled. > But someone is cautious can enable it on a need basis by knowing the > possible reduction on throughput number. Then I think a module parameter would be the best approach, I don't see the need to recompile anything for this. And remember to document the impact for the performance in the commit log and/or in the module parameter documentation. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wireless/microchip/wilc1000/spi.c index be732929322c..d11e365eeee2 100644 --- a/drivers/net/wireless/microchip/wilc1000/spi.c +++ b/drivers/net/wireless/microchip/wilc1000/spi.c @@ -11,6 +11,16 @@ #include "netdev.h" #include "cfg80211.h" +/* + * For CMD_SINGLE_READ and CMD_INTERNAL_READ, WILC may insert one or + * more zero bytes between the command response and the DATA Start tag + * (0xf3). This behavior appears to be undocumented in "ATWILC1000 + * USER GUIDE" (https://tinyurl.com/4hhshdts) but we have observed 1-4 + * zero bytes when the SPI bus operates at 48MHz and none when it + * operates at 1MHz. + */ +#define WILC_SPI_RSP_HDR_EXTRA_DATA 8 + struct wilc_spi { int crc_off; }; @@ -79,16 +89,15 @@ struct wilc_spi_cmd { } __packed; struct wilc_spi_read_rsp_data { - u8 rsp_cmd_type; - u8 status; - u8 resp_header; - u8 resp_data[4]; + u8 header; + u8 data[4]; u8 crc[]; } __packed; struct wilc_spi_rsp_data { u8 rsp_cmd_type; u8 status; + u8 data[]; } __packed; static int wilc_bus_probe(struct spi_device *spi) @@ -359,10 +368,11 @@ static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b, struct spi_device *spi = to_spi_device(wilc->dev); struct wilc_spi *spi_priv = wilc->bus_data; u8 wb[32], rb[32]; - int cmd_len, resp_len; u8 crc[2]; + int cmd_len, resp_len, i; struct wilc_spi_cmd *c; - struct wilc_spi_read_rsp_data *r; + struct wilc_spi_read_rsp_data *r_data; + struct wilc_spi_rsp_data *r; memset(wb, 0x0, sizeof(wb)); memset(rb, 0x0, sizeof(rb)); @@ -384,7 +394,8 @@ static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b, } cmd_len = offsetof(struct wilc_spi_cmd, u.simple_cmd.crc); - resp_len = sizeof(*r); + resp_len = sizeof(*r) + sizeof(*r_data) + WILC_SPI_RSP_HDR_EXTRA_DATA; + if (!spi_priv->crc_off) { c->u.simple_cmd.crc[0] = wilc_get_crc7(wb, cmd_len); cmd_len += 1; @@ -403,7 +414,7 @@ static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b, return -EINVAL; } - r = (struct wilc_spi_read_rsp_data *)&rb[cmd_len]; + r = (struct wilc_spi_rsp_data *)&rb[cmd_len]; if (r->rsp_cmd_type != cmd) { dev_err(&spi->dev, "Failed cmd response, cmd (%02x), resp (%02x)\n", @@ -417,17 +428,22 @@ static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b, return -EINVAL; } - if (WILC_GET_RESP_HDR_START(r->resp_header) != 0xf) { - dev_err(&spi->dev, "Error, data read response (%02x)\n", - r->resp_header); + for (i = 0; i < WILC_SPI_RSP_HDR_EXTRA_DATA; ++i) + if (WILC_GET_RESP_HDR_START(r->data[i]) == 0xf) + break; + + if (i >= WILC_SPI_RSP_HDR_EXTRA_DATA) { + dev_err(&spi->dev, "Error, data start missing\n"); return -EINVAL; } + r_data = (struct wilc_spi_read_rsp_data *)&r->data[i]; + if (b) - memcpy(b, r->resp_data, 4); + memcpy(b, r_data->data, 4); if (!spi_priv->crc_off) - memcpy(crc, r->crc, 2); + memcpy(crc, r_data->crc, 2); return 0; }
For CMD_SINGLE_READ and CMD_INTERNAL_READ, WILC may insert one or more zero bytes between the command response and the DATA Start tag (0xf3). This behavior appears to be undocumented in "ATWILC1000 USER GUIDE" (https://tinyurl.com/4hhshdts) but we have observed 1-4 zero bytes when the SPI bus operates at 48MHz and none when it operates at 1MHz. This code is derived from the equivalent code of the wilc driver in the linux-at91 repository. Signed-off-by: David Mosberger-Tang <davidm@egauge.net> --- drivers/net/wireless/microchip/wilc1000/spi.c | 42 +++++++++++++------ 1 file changed, 29 insertions(+), 13 deletions(-)