summaryrefslogtreecommitdiff
path: root/tools/perf/scripts/python/parallel-perf.py
diff options
context:
space:
mode:
authorNikhil Solanke <nikhilsolanke5@gmail.com>2026-07-29 01:21:57 +0530
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2026-08-03 17:25:30 +0200
commit152f174a13618bec1f842d2deb69245cb2ace51f (patch)
tree11befc806ed006a87d673ce37dec730cae110ef3 /tools/perf/scripts/python/parallel-perf.py
parentc2f811314be351d86b6ab41e9297ae80d8da6f86 (diff)
usb: core: Add quirk for 255-bytes initial config read
Certain third-party USB game controllers exposing (or spoofing) an Xbox 360-compatible interface (VID:PID 045e:028e) fail to enumerate under Linux. The device disconnects from the bus without responding to the initial GET_DESCRIPTOR(CONFIGURATION) request, and the kernel logs 'unable to read config index 0 descriptor/start: -71'. The device then falls back to a secondary Android HID mode (with a different VID:PID), losing XInput functionality including rumble support. The failure reproduces across multiple machines, host controller types, and kernel versions including current mainline and LTS. The device enumerates correctly and remains in XInput mode under Windows. Notably, the device enumerates correctly in Android mode when the same 9-byte request is issued for that mode's configuration descriptor, confirming the firmware bug is specific to the XInput mode. usbmon traces from Linux and Wireshark/USBPcap traces from Windows are identical up to the point of failure, with no visible protocol-level difference explaining the divergence. The root cause was identified when Michal Pecio discovered via a QEMU bus-level capture that Windows does not use wLength=9 for the initial config descriptor request; it uses wLength=255. Alan Stern subsequently confirmed this with a bus analyzer on a different USB 2.0 device, and Michal verified the behavior goes back to Windows 95 OSR2.1. So, add a new quirk flag USB_QUIRK_WINDOWS_CONFIG_REQ_SIZE which causes usb_get_configuration() to issue a 255 byte sized configuration request instead of USB_DT_CONFIG_SIZE (9) for the initial GET_DESCRIPTOR(CONFIGURATION) request, mimicking long-standing Windows behavior. This patch intentionally does not add any new VID:PID entries using this quirk. Some affected Xbox 360-compatible controllers spoof Microsoft's VID:PID, while genuine Microsoft controllers already enumerate correctly and do not require this quirk. Other affected clone devices use their own VID:PID pairs and can be added individually as they are identified. Suggested-by: Alan Stern <stern@rowland.harvard.edu> Suggested-by: Michal Pecio <michal.pecio@gmail.com> Closes: https://lore.kernel.org/linux-usb/CAFgddh+JWdT4LLwMc5qjM8q_pBu-fRo2qADR5ovAKoGHWMQrRw@mail.gmail.com/ Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable <stable@kernel.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Nikhil Solanke <nikhilsolanke5@gmail.com> Link: https://patch.msgid.link/20260728195158.65162-2-nikhilsolanke5@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/perf/scripts/python/parallel-perf.py')
0 files changed, 0 insertions, 0 deletions