From: Michael Zaidman michael.zaidman@gmail.com
[ Upstream commit db8d3a21275c807a4047a21bde3b57d49ca55d82 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hid/hid-ft260.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index f43a8406cb9a..e73776ae6976 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 @@ 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);