https://github.com/torvalds/linux
Revision db8d3a21275c807a4047a21bde3b57d49ca55d82 authored by Michael Zaidman on 29 July 2021, 10:26:03 UTC, committed by Jiri Kosina on 29 July 2021, 10:38:32 UTC
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>
1 parent 7cc8524
Tip revision: db8d3a21275c807a4047a21bde3b57d49ca55d82 authored by Michael Zaidman on 29 July 2021, 10:26:03 UTC
HID: ft260: fix device removal due to USB disconnect
HID: ft260: fix device removal due to USB disconnect
Tip revision: db8d3a2
File | Mode | Size |
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Documentation | ||
LICENSES | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | -rw-r--r-- | 16.6 KB |
.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 71 bytes |
.gitattributes | -rw-r--r-- | 62 bytes |
.gitignore | -rw-r--r-- | 1.9 KB |
.mailmap | -rw-r--r-- | 19.7 KB |
COPYING | -rw-r--r-- | 496 bytes |
CREDITS | -rw-r--r-- | 98.6 KB |
Kbuild | -rw-r--r-- | 1.3 KB |
Kconfig | -rw-r--r-- | 555 bytes |
MAINTAINERS | -rw-r--r-- | 590.4 KB |
Makefile | -rw-r--r-- | 64.4 KB |
README | -rw-r--r-- | 727 bytes |
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