1. 19 Feb, 2016 1 commit
    • Charles Keepax's avatar
      ASoC: samsung: Use IRQ safe spin lock calls · 316fa9e0
      Charles Keepax authored
      Lockdep warns of a potential lock inversion, i2s->lock is held numerous
      times whilst we are under the substream lock (snd_pcm_stream_lock). If
      we use the IRQ unsafe spin lock calls, you can also end up locking
      snd_pcm_stream_lock whilst under i2s->lock (if an IRQ happens whilst we
      are holding i2s->lock). This could result in deadlock.
      
      [   18.147001]        CPU0                    CPU1
      [   18.151509]        ----                    ----
      [   18.156022]   lock(&(&pri_dai->spinlock)->rlock);
      [   18.160701]                                local_irq_disable();
      [   18.166622]                                lock(&(&substream->self_group.lock)->rlock);
      [   18.174595]                                lock(&(&pri_dai->spinlock)->rlock);
      [   18.181806]   <Interrupt>
      [   18.184408]     lock(&(&substream->self_group.lock)->rlock);
      [   18.190045]
      [   18.190045]  *** DEADLOCK ***
      
      This patch changes to using the irq safe spinlock calls, to avoid this
      issue.
      
      Fixes: ce8bcdbb ("ASoC: samsung: i2s: Protect more registers with a spinlock")
      Signed-off-by: default avatarCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
      Tested-by: default avatarAnand Moon <linux.amoon@gmail.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Cc: stable@vger.kernel.org
      316fa9e0
  2. 24 Jan, 2016 39 commits