From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Mack Subject: Re: [Bug 46011] Capture of sound from USB connected audio card (UGM96) doesn't work in 3.5.1 - kernel bug generated: scheduling while atomic Date: Thu, 16 Aug 2012 12:28:13 +0200 Message-ID: <502CCB3D.3070506@gmail.com> References: <20120815103121.D4D5211FC6C@bugzilla.kernel.org> <502B7B5B.1030808@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-bk0-f51.google.com (mail-bk0-f51.google.com [209.85.214.51]) by alsa0.perex.cz (Postfix) with ESMTP id 4DFBD26537D for ; Thu, 16 Aug 2012 11:58:31 +0200 (CEST) Received: by bkcjk13 with SMTP id jk13so771000bkc.38 for ; Thu, 16 Aug 2012 03:28:17 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Clemens Ladisch Cc: Takashi Iwai , alsa-devel List-Id: alsa-devel@alsa-project.org On 15.08.2012 12:40, Takashi Iwai wrote: >>> Could you try the patch below? Clemens, the patch below fixes a "sleeping while atomic" bug in the USB audio driver, but it raises a new "not enough bandwidth" issue, which might even be unreleated. I currently don't see the root cause here, but I might be blind. Do you have any idea? Thanks, Daniel > --- > From: Takashi Iwai > Subject: [PATCH] ALSA: usb-audio: Fix scheduling-while-atomic bug in PCM > capture stream > > A PCM capture stream on usb-audio causes a scheduling-while-atomic > BUG, as reported in the bugzilla entry below. It's because > snd_usb_endpoint_start() is called at first at trigger START for a > capture stream, and this function contains the left-over EP > deactivation codes. The problem doesn't happen for a playback stream > because the function is called at PCM prepare time, which can sleep. > > This patch fixes the BUG by moving the EP deactivation code into the > PCM prepare callback. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=46011 > Cc: [v3.5+] > Signed-off-by: Takashi Iwai > --- > sound/usb/endpoint.c | 4 ---- > sound/usb/pcm.c | 3 +++ > 2 files changed, 3 insertions(+), 4 deletions(-) > > diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c > index 0f647d2..c411812 100644 > --- a/sound/usb/endpoint.c > +++ b/sound/usb/endpoint.c > @@ -821,10 +821,6 @@ int snd_usb_endpoint_start(struct snd_usb_endpoint *ep) > if (++ep->use_count != 1) > return 0; > > - /* just to be sure */ > - deactivate_urbs(ep, 0, 1); > - wait_clear_urbs(ep); > - > ep->active_mask = 0; > ep->unlink_mask = 0; > ep->phase = 0; > diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c > index a1298f3..62ec808 100644 > --- a/sound/usb/pcm.c > +++ b/sound/usb/pcm.c > @@ -544,6 +544,9 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream) > subs->last_frame_number = 0; > runtime->delay = 0; > > + /* clear the pending deactivation on the target EPs */ > + deactivate_endpoints(subs); > + > /* for playback, submit the URBs now; otherwise, the first hwptr_done > * updates for all URBs would happen at the same time when starting */ > if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) >