Being affected by this bug, I can confirm that Linux 3.11-rc4 still exhibits the unwanted behaviour for me, but that commenting out the single line from the second patch makes it work. Thus, for requesting a revert on that line, you are most welcome to put me down as a "Tested-By". Best regards, Sune Mølgaard Benjamin Tissoires wrote: > On Mon, Aug 5, 2013 at 3:22 PM, Jiri Kosina <jkosina@xxxxxxx> wrote: >> On Fri, 2 Aug 2013, Benjamin Tissoires wrote: >> >>>> Could you please elaborate? (and put an elaborate description to revert >>>> commit log perhaps?) >>> >>> Sure, so here is the revert commit log: >>> >>> -- >>> >>> Commit "HID: hid-logitech-dj, querying_devices was never set" activate >>> a flag which guarantees that we do not ask the receiver for too many >>> enumeration. When the flag is set, each following enumeration call is >>> discarded (the usb request is not forwarded to the receiver). The flag >>> is then released when the driver receive a pairing information event, >>> which normally follows the enumeration request. >>> However, the USB3 bug makes the driver think the enumeration request >>> has been forwarded to the receiver. However, it is actually not the >>> case because the USB stack returns -EPIPE. So, when a new unknown >>> device appears, the workaround consisting in asking for a new >>> enumeration is not working anymore: this new enumeration is discarded >>> because of the flag, which is never reset. >>> >>> A solution could be to trigger a timeout before releasing it, but for >>> now, let's just revert the patch. >>> >>> -- >> >> Thanks Benjamin. >> >> I'd like to have a bit more clarification about the USB3 bug, as this >> whole issue is not completely clear to me. >> >> To be more specific -- when exactly do we receive -EPIPE, why do we >> receive it and why do we not handle it properly? > > Sure, I'll try (though the more I think of it, the more it seems > blurry to me :( ). > > So the initial probe function in hid-logitech-dj was implemented by > using a direct call to hid_output_raw_report(). This call was > synchronous, so we did get the -EPIPE return code. Then, the probe() > function returns the -EPIPE error, cleaning the receiver and > unregister it from the hid bus. > > However, now, we use hid_hw_request(), which is asynchronous (from > what I can read). At least, this code returns "void" as the set_report > command seems to be scheduled for later handling. In usbhid, when the > queue is flushed, I did not found a way to retrieve the error code... > > So basically, the -EPIPE is received in usbhid_restart_ctrl_queue(), > but nothing notifies hid-logitech-dj from the error. In the end, the > probe() function returns without error code, but the receiver never > received the notification. > > Cheers, > Benjamin > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > > -- "Testiculos habet et bene pendentes" See http://www.newint.org/features/1993/06/05/curious/ -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
