diff options
author | Michael Zaidman <michael.zaidman@gmail.com> | 2021-07-29 13:26:03 +0300 |
---|---|---|
committer | Jiri Kosina <jkosina@suse.cz> | 2021-07-29 13:38:32 +0300 |
commit | db8d3a21275c807a4047a21bde3b57d49ca55d82 (patch) | |
tree | 72c80fc5756c11e28d51800596d6e641ab836f4a /drivers/hid/hid-ft260.c | |
parent | 7cc8524f65ce1a350042836c7cf837046aaa6e21 (diff) | |
download | linux-db8d3a21275c807a4047a21bde3b57d49ca55d82.tar.xz |
HID: ft260: fix device removal due to USB disconnect
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>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid/hid-ft260.c')
-rw-r--r-- | drivers/hid/hid-ft260.c | 23 |
1 files changed, 7 insertions, 16 deletions
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 6f10df2042c4..4ef1c3b8094e 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -742,7 +742,7 @@ static int ft260_is_interface_enabled(struct hid_device *hdev) int ret; ret = ft260_get_system_config(hdev, &cfg); - if (ret) + if (ret < 0) return ret; ft260_dbg("interface: 0x%02x\n", interface); @@ -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 @@ err_hid_stop: 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); |