Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752860Ab3HENWU (ORCPT ); Mon, 5 Aug 2013 09:22:20 -0400 Received: from cantor2.suse.de ([195.135.220.15]:54001 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752485Ab3HENWS (ORCPT ); Mon, 5 Aug 2013 09:22:18 -0400 Date: Mon, 5 Aug 2013 15:22:13 +0200 (CEST) From: Jiri Kosina To: Benjamin Tissoires Cc: Nestor Lopez Casado , Andrew de los Reyes , joseph.salisbury@canonical.com, linux-input , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/2] HID: hid-logitech-dj, querying_devices was never set In-Reply-To: Message-ID: References: <1374153691-25100-1-git-send-email-nlopezcasad@logitech.com> <1374153691-25100-2-git-send-email-nlopezcasad@logitech.com> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1663 Lines: 45 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? Thanks again, -- Jiri Kosina SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/