Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933054Ab2HPQbK (ORCPT ); Thu, 16 Aug 2012 12:31:10 -0400 Received: from smtprelay.restena.lu ([158.64.1.62]:43674 "EHLO smtprelay.restena.lu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932942Ab2HPQbH convert rfc822-to-8bit (ORCPT ); Thu, 16 Aug 2012 12:31:07 -0400 Date: Thu, 16 Aug 2012 18:30:21 +0200 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= To: Jiri Kosina Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org Subject: Re: [PATCH 0/7] HID: picoLCD updates Message-ID: <20120816183021.68c37f37@neptune.home> In-Reply-To: References: <20120730213656.0a9f6d30@neptune.home> <20120815114236.0f7db40e@neptune.home> <20120815171635.2564a4a8@neptune.home> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2410 Lines: 52 On Wed, 15 August 2012 Jiri Kosina wrote: > On Wed, 15 Aug 2012, Bruno Prémont wrote: > > > I see. Alan Stern has fixed a huge pile of things in this area in 3.6-rc1. > > > I have expected all of those to actually be on theoretical problems not > > > ever having happened in the wild, but it might be that you are actually > > > chasing on of those. > > > > > > Could you please retest with latest Linus' tree (or at least eb055fd0560b) > > > to see whether this hasn't actually been fixed already by Alan's series? > > > > I've started trying that out, it seems Alan's work improved things. > > > > For the first few attempts I have not seen SLAB corruptions, though after > > a few rounds I hit accumulation of the following messages: > > [ 297.174828] hid-picolcd 0003:04D8:C002.0003: output queue full > > [ 297.181098] hid-picolcd 0003:04D8:C002.0003: output queue full > > [ 297.187820] hid-picolcd 0003:04D8:C002.0003: output queue full > > [ 297.194087] hid-picolcd 0003:04D8:C002.0003: output queue full > > > > with sporadically in between: > > [ 292.668019] hid-picolcd 0003:04D8:C002.0003: usb_submit_urb(out) failed: -1 > > > > At first glance I think the queue filling up and never draining is caused > > by hid_hw_stop() stalling the queue and the time between both being just too > > short. > > I don't really understand this explanation. Once usb_kill_urb() returns, > the URB should be available for future use (and therefore all queues > completely drained). I won't have time today to check, though my guess is that on each echo $usb-id > bind; echo $usb-id > unbind under /sys/bus/hid/drivers/hid-picolcd/ the USB urb queue fills a bit does not get cleared. Is usb_kill_urb() called when unbinding just the specific hid driver? If so my short timing between bind/unbind must be triggering something else... Otherwise I'm missing something as at first time I got no "output queue full" messages, but as I repeated the bind/unbind sequences the prints per bind/unbind iteration increased in number. Anyhow, on Friday evening/week-end I will continue digging and report back with my findings. Thanks, Bruno -- 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/