Messages in this thread | | | Date | Tue, 18 Aug 2020 19:52:19 +0200 (CEST) | From | Jiri Kosina <> | Subject | Re: [PATCH v2] HID: usbhid: do not sleep when opening device |
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On Tue, 18 Aug 2020, Johannes Hirte wrote:
> > usbhid tries to give the device 50 milliseconds to drain its queues when > > opening the device, but dies it naively by simply sleeping in open handler, > > which slows down device probing (and thus may affect overall boot time). > > > > However we do not need to sleep as we can instead mark a point of time in > > the future when we should start processing the events. > > > > Reported-by: Nicolas Boichat <drinkcat@chromium.org> > > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > > --- > > > > This change breaks various Logitech devices: > https://bugzilla.kernel.org/show_bug.cgi?id=208935
Copy/pasting from the other thread:
===== Yeah, this problem popped out also in other contexts, where many Logitech devices didn't probe properly, because of the race where the first IRQ is dropped on the floor (after hid_device_io_start() happens, but before the 50ms timeout passess), and report descriptor never gets parsed and populated.
As this is just a boot time micro-optimization, I am going to revert the patch for 5.9 now, and we can try to fix this properly for next merge window. =====
Thanks,
-- Jiri Kosina SUSE Labs
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