The commit "usb: gadget: f_hid: fix f_hidg lifetime vs cdev" (89ff3dfac604614287ad5aad9370c3f984ea3f4b) has introduced a bug that leads to hid device corruption after the replug operation. The usb gadget driver bug was observed in the KVM functionality of the OpenBMC distribution. In the test environment BMC provides KVM functionality for the host (i.e. virtual USB keyboard) via the USB gadget device. The bug occurs when the KVM page is refreshed (i.e. USB device is replugged). Before the 89ff3dfac6 this opeartion was working without any issues. Log messages from the host for this operation: ``` kernel: usb 1-7.4: USB disconnect, device number 3 kernel: usb 1-7.4: new high-speedUSB device number 4 using xhci_hcd kernel: usb 1-7.4: New USB device found, idVendor=1d6b, idProduct=0104, bcdDevice= 1.00 kernel: usb 1-7.4: New USB device strings: Mfr=1, Produt=2, SerialNumber=3 kernel: usb 1-7.4: Product: Virtual Keyboard and Mouse kernel: usb 1-7.4: Manufacturer: OpenBMC kernel: usb 1-7.4: SerialNumber: OBMC0001 kernel: input: OpenBMC Virtual Keyboard and Mouse as /devices/pci0000: 00/0000:00:140/usb1/1-7/1-7.4/1-7.4:1.0/0003:1D6B:0104.0003/input/input3 kernel: hid-generic 0003:1D6B:0104.0003: inputhidraw0: USB HID v1.01 Keyboard [OpenBMC Virtual Keyboard and Mouse] on usb-0000:00:14.0-7.4/input0 kernel: input: OpenBMC Virtual Keyboard and Mouse as /devices/pci0000: 00/0000:00:14.0/sb1/1-7/1-7.4/1-7.4:1.1/0003:1D6B:0104.0004/input/input4 kernel: hid-generic 0003:1D6B:0104.0004: input,hidraw1: USB HID v1.01 Mouse [OpenBMC Virtual Keyboard and Mouse] on usb-0000:00:14.0-7.4/input1 ``` After the 89ff3dfac6 the KVM page refresh (i.e. USB device replug) results to the USB device corruction and the following messages from the driver: ``` kernel: usb 1-7.4: USB disconnect, device number 3 hid-generic 0003:1D6B:0104.0003: item fetching failed at offset 18/63 hid-generic 0003:1D6B:01040004: item fetching failed at offset 32/76 kernel: usb 1-7.4: new high-speed USB device number 4 using xhci_hcd kernel: usb 1-7.4: New USB device found, idVendor=1d6b, idProduct=0104, bcdDevice= 1.00 kernel: usb 1-7.4:New USB device strings: Mfr=1, Product=2, SerialNumber=3 kernel: usb 1-7.4: Product: Virual Keyboard and Mouse kernel: usb 1-7.4: Manufacturer: OpenBMC kernel: usb 1-7.4: SerialNumber: OBMC0001 kernel: id-generic 0003:1D6B:0104.0003: unknown main item tag 0x0 kernel: hid-generic 0003:1D6B:0104.0003: unknown main item tag 0x0 kernel: hid-generic 0003:1D6B:0104.0003: unknown main item tag 0x0 kernel: hid-generic 0003:1D6B:0104.0003: unknown main item tag 0x0 kernel: hid-generic 0003:1D6B:0104.0003: unknown main item tag 0x0 kernel: hid-generic 0003:1D6B:0104.0003: unknown main item tag 0x0 kernel: hid-generic 0003:1D6B:0104.0003: unknown main item tag 0x0 kernel: hid-generic 0003:1D6B:0104.0003: unknown main item tag 0x0 kernel: hid-generic 0003:1D6B:0104.0003: unknown main item tag 0x0 kernel: hid-generic 0003:1D6B:0104.0003: unknown main item ag 0x0 kernel: hid-generic 0003:1D6B:0104.0003: item fetching failed at offset 18/63 kernel: hid-eneric: probe of 0003:1D6B:0104.0003 failed with error -22 kernel: hid-generic 0003:1D6B:0104.0004: item fetching failed at offset 32/76 kernel hid-generic: probe of 0003:1D6B:0104.0004 failed with error -22 ``` Reverse device managed memory allocation for the report descriptor to fix the issue. Changes v1 -> v2: - update commit message Konstantin Aladyshev (1): usb: gadget: f_hid: fix report descriptor allocation drivers/usb/gadget/function/f_hid.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) -- 2.25.1
