| Message ID | 20210720144954.5392-1-michael.zaidman@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v1] HID: ft260: fix device removal due to USB disconnect | expand |
On Tue, 20 Jul 2021, Michael Zaidman wrote: > This commit fixes a regression introduced by the commit 82f09a637dd3 > ("HID: ft260: improve error handling of ft260_hid_feature_report_get()") > when upon USB disconnect, the ft260 i2c device is still available within > the /dev folder. Thanks for the fix. Could you please make the changelog a little bit more verbose though? Namely describe the issue in the code the patch is fixing (and how). Thanks, -- Jiri Kosina SUSE Labs
On Thu, 29 Jul 2021, Michael Zaidman wrote: > This commit fixes a functional regression introduced by the commit 82f09a637dd3 > ("HID: ft260: improve error handling of ft260_hid_feature_report_get()") > when upon USB disconnect, the FTDI FT260 i2c device is still available within > the /dev folder. > > In my company's product, where the host USB to FT260 USB connection is > hard-wired in the PCB, the issue is not reproducible. To reproduce it, I used > the VirtualBox Ubuntu 20.04 VM and the UMFT260EV1A development module for the > FTDI FT260 chip: > > Plug the UMFT260EV1A module into a USB port and attach it to VM. > > The VM shows 2 i2c devices under the /dev: > michael@michael-VirtualBox:~$ ls /dev/i2c-* > /dev/i2c-0 /dev/i2c-1 > > The i2c-0 is not related to the FTDI FT260: > michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-0/name > SMBus PIIX4 adapter at 4100 > > The i2c-1 is created by hid-ft260.ko: > michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-1/name > FT260 usb-i2c bridge on hidraw1 > > Now, detach the FTDI FT260 USB device from VM. We expect the /dev/i2c-1 > to disappear, but it's still here: > michael@michael-VirtualBox:~$ ls /dev/i2c-* > /dev/i2c-0 /dev/i2c-1 > > And the kernel log shows: > [ +0.001202] usb 2-2: USB disconnect, device number 3 > [ +0.000109] ft260 0003:0403:6030.0002: failed to retrieve system status > [ +0.000316] ft260 0003:0403:6030.0003: failed to retrieve system status > > It happens because the commit 82f09a637dd3 changed the ft260_get_system_config() > return logic. This caused the ft260_is_interface_enabled() to exit with error > upon the FT260 device USB disconnect, which in turn, aborted the ft260_remove() > before deleting the FT260 i2c device and cleaning its sysfs stuff. > > This commit restores the FT260 USB removal functionality and improves the > ft260_is_interface_enabled() code to handle correctly all chip modes defined > by the device interface configuration pins DCNF0 and DCNF1. > > Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com> > Acked-by: Aaron Jones (FTDI-UK) <aaron.jones@ftdichip.com> Thanks for the respin. Queued in for-5.14/upstream-fixes. -- Jiri Kosina SUSE Labs
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index f43a8406cb9a..fa73a35aaf98 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -742,8 +742,8 @@ static int ft260_is_interface_enabled(struct hid_device *hdev) int ret; ret = ft260_get_system_config(hdev, &cfg); - if (ret) - return ret; + if (ret < 0) + return 0; ft260_dbg("interface: 0x%02x\n", interface); ft260_dbg("chip mode: 0x%02x\n", cfg.chip_mode); @@ -754,23 +754,16 @@ static int ft260_is_interface_enabled(struct hid_device *hdev) switch (cfg.chip_mode) { case FT260_MODE_ALL: case FT260_MODE_BOTH: - if (interface == 1) { + if (interface == 1) hid_info(hdev, "uart interface is not supported\n"); - return 0; - } - ret = 1; + else + ret = 1; break; case FT260_MODE_UART: - if (interface == 0) { - hid_info(hdev, "uart is unsupported on interface 0\n"); - ret = 0; - } + hid_info(hdev, "uart interface is not supported\n"); break; case FT260_MODE_I2C: - if (interface == 1) { - hid_info(hdev, "i2c is unsupported on interface 1\n"); - ret = 0; - } + ret = 1; break; } return ret; @@ -1004,11 +997,9 @@ static int ft260_probe(struct hid_device *hdev, const struct hid_device_id *id) static void ft260_remove(struct hid_device *hdev) { - int ret; struct ft260_device *dev = hid_get_drvdata(hdev); - ret = ft260_is_interface_enabled(hdev); - if (ret <= 0) + if (!dev) return; sysfs_remove_group(&hdev->dev.kobj, &ft260_attr_group);
This commit fixes a regression introduced by the commit 82f09a637dd3 ("HID: ft260: improve error handling of ft260_hid_feature_report_get()") when upon USB disconnect, the ft260 i2c device is still available within the /dev folder. Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com> Acked-by: Aaron Jones (FTDI-UK) <aaron.jones@ftdichip.com> --- drivers/hid/hid-ft260.c | 25 ++++++++----------------- 1 file changed, 8 insertions(+), 17 deletions(-)