Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932169Ab1CRGzr (ORCPT ); Fri, 18 Mar 2011 02:55:47 -0400 Received: from cantor2.suse.de ([195.135.220.15]:45402 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932114Ab1CRGzn (ORCPT ); Fri, 18 Mar 2011 02:55:43 -0400 Date: Fri, 18 Mar 2011 07:55:36 +0100 Message-ID: From: Takashi Iwai To: Knut Petersen Cc: Linus Torvalds , Jaroslav Kysela , Chris Wilson , jesse.barnes@intel.com, gregkh@suse.de, linux-kernel@vger.kernel.org, David =?UTF-8?B?TcO8bGxlcg==?= Subject: Re: [BUG][2.6.38] IRQ Lock Inversion / i915 fails In-Reply-To: <4D82957A.1080200@t-online.de> References: <4D81D6F9.3040304@t-online.de> <4D82957A.1080200@t-online.de> User-Agent: Wanderlust/2.15.6 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.7 Emacs/23.2 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") 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: 2529 Lines: 83 At Fri, 18 Mar 2011 00:12:58 +0100, Knut Petersen wrote: > > Thanks a lot. That patch below does indeed > solve the irq lock inversion problem. Thanks for testing. I applied the patch now. Takashi > > cu, > Knut > > > > > The trigger callback should be called always in irq-disabled context, > > so this should be OK. But loopback_pos_update() is called in the > > timer callback, and this can be the issue. > > > > Knut, how about the patch below? > > > > > > thanks, > > > > Takashi > > > > --- > > diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c > > index 12b44b0..a0da775 100644 > > --- a/sound/drivers/aloop.c > > +++ b/sound/drivers/aloop.c > > @@ -482,8 +482,9 @@ static unsigned int loopback_pos_update(struct loopback_cable *cable) > > cable->streams[SNDRV_PCM_STREAM_CAPTURE]; > > unsigned long delta_play = 0, delta_capt = 0; > > unsigned int running; > > + unsigned long flags; > > > > - spin_lock(&cable->lock); > > + spin_lock_irqsave(&cable->lock, flags); > > running = cable->running ^ cable->pause; > > if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) { > > delta_play = jiffies - dpcm_play->last_jiffies; > > @@ -495,10 +496,8 @@ static unsigned int loopback_pos_update(struct loopback_cable *cable) > > dpcm_capt->last_jiffies += delta_capt; > > } > > > > - if (delta_play == 0 && delta_capt == 0) { > > - spin_unlock(&cable->lock); > > - return running; > > - } > > + if (delta_play == 0 && delta_capt == 0) > > + goto unlock; > > > > if (delta_play > delta_capt) { > > loopback_bytepos_update(dpcm_play, delta_play - delta_capt, > > @@ -510,14 +509,14 @@ static unsigned int loopback_pos_update(struct loopback_cable *cable) > > delta_capt = delta_play; > > } > > > > - if (delta_play == 0 && delta_capt == 0) { > > - spin_unlock(&cable->lock); > > - return running; > > - } > > + if (delta_play == 0 && delta_capt == 0) > > + goto unlock; > > + > > /* note delta_capt == delta_play at this moment */ > > loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY); > > loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY); > > - spin_unlock(&cable->lock); > > + unlock: > > + spin_unlock_irqrestore(&cable->lock, flags); > > return running; > > } > > > > > -- 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/