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authorMichael Zaidman2021-07-29 13:26:03 +0300
committerJiri Kosina2021-07-29 12:38:32 +0200
commitdb8d3a21275c807a4047a21bde3b57d49ca55d82 (patch)
tree72c80fc5756c11e28d51800596d6e641ab836f4a /drivers/hid
parent7cc8524f65ce1a350042836c7cf837046aaa6e21 (diff)
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')
-rw-r--r--drivers/hid/hid-ft260.c23
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);