On Tue, Apr 19, 2022 at 05:51:38PM +0200, Oliver Neukum wrote: > > > On 19.04.22 16:35, Alan Stern wrote: > > On Tue, Apr 19, 2022 at 09:05:53AM +0200, Oliver Neukum wrote: > > > > > > We have a set of quirky devices that need HID_QUIRK_ALWAYS_POLL. > > They have the nasty firmware bug that, if you suspend them without > > remote wakeup, they will crash or reset themselves. > > I am afraid that has an obvious relevance to your cool patches. > > I am not completely sure how to deal with this. It seems to me that the > > quirk will need to be shifted from HID to core USB and thaw() needs to > > be translated into usb_device_reset() + reset_resume() for them, > > but I am not really sure about the optimal mechanism. > > We may not need to do anything. This patch specifically addresses > > hibernation, not system suspend or runtime suspend. A device crashing > > or resetting during hibernation is not at all unusual; we should be able > > to handle such cases properly. > > > > The THAW part of suspend-to-hibernation is used only for writing the > > memory image to permanent storage. I doubt that a malfunctioning HID > > device would interfere with this process. > > > True, if and only if all goes well. At the time thaw() has run writing > the image to disk can still fail. In that case the devices will still > be needed. Consider adding a mechanism to usbcore which would allow an interface driver to request that the next time its device is resumed, the core should perform a reset-resume. Would that help? Alan Stern
