target/linux/layerscape/patches-5.4/806-dma-0011-MLK-16482-dma-fsl-edma-v3-Fix-RCU-issue-while-playin.patch

   1 From 46c343673c6eae7909f644f9b67101ce14309670 Mon Sep 17 00:00:00 2001
   2 From: Robin Gong <yibin.gong@nxp.com>
   3 Date: Tue, 19 Sep 2017 11:36:58 +0800
   4 Subject: [PATCH] MLK-16482: dma: fsl-edma-v3: Fix RCU issue while playing
   5  Audio
   6
   7 That's caused by commit 593034f1b908 ("MLK-16437: dma: fsl-edma-v3:
   8 fix kernel crash while edma interrupt trigger after channel disabled").
   9 Because fsl_chan->vchan.lock will be hold always and trigger RCU report
  10 as below:
  11
  12 1571.3  Playing WAVE '/mnt/nfs/vte_mx82/../test_stream/esai_stream/48k16bit-six.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Channels 6
  13 1571.5  [ 4642.698771] INFO: rcu_preempt detected stalls on CPUs/tasks:
  14 1571.6  [ 4642.704443] 0-...: (1 GPs behind) idle=2c5/140000000000000/0 softirq=155373/155374 fqs=2541
  15 1571.7  [ 4642.712967] (detected by 2, t=5252 jiffies, g=104259, c=104258, q=22)
  16 1571.8  [ 4642.719501] Task dump for CPU 0:
  17 1571.9  [ 4642.722724] aplay R running task 0 15723 15721 0x00000202
  18 1571.10  [ 4642.729786] Call trace:
  19 1571.11  [ 4642.732239] [<ffff0000080855e4>] __switch_to+0x8c/0xa0
  20 1571.12  [ 4642.737379] [<ffff0000084e3a48>] dma_chan_put+0x70/0xa0
  21 1571.13  [ 4642.742603] [<ffff0000084e3aac>] dma_release_channel+0x34/0xa0
  22 1571.14  [ 4642.748435] [<ffff000008972240>] fsl_asrc_dma_hw_free+0x38/0x50
  23 1571.15  [ 4642.754358] [<ffff000008960568>] soc_pcm_hw_free+0x110/0x1a8
  24 1571.16  [ 4642.760013] [<ffff000008963bcc>] dpcm_fe_dai_hw_free+0x6c/0xe0
  25 1571.17  [ 4642.765844] [<ffff000008948ae8>] snd_pcm_common_ioctl1+0xb40/0xce0
  26 1571.18  [ 4642.772028] [<ffff000008948e64>] snd_pcm_playback_ioctl1+0x1dc/0x310
  27 1571.19  [ 4642.778378] [<ffff000008948fc0>] snd_pcm_playback_ioctl+0x28/0x40
  28 1571.20  [ 4642.784470] [<ffff0000081ee0a4>] do_vfs_ioctl+0xa4/0x748
  29 1571.21  [ 4642.789784] [<ffff0000081ee7d4>] SyS_ioctl+0x8c/0xa0
  30 1571.22  [ 4642.794745] [<ffff000008082f4c>] __sys_trace_return+0x0/0x4
  31 1571.23  [ 4705.718740] INFO: rcu_preempt detected stalls on CPUs/tasks:
  32 1571.24  [ 4705.724420] 0-...: (1 GPs behind) idle=2c5/140000000000000/0 softirq=155373/155374 fqs=10407
  33 1571.25  [ 4705.733030] (detected by 1, t=21010 jiffies, g=104259, c=104258, q=119)
  34
  35 Signed-off-by: Robin Gong <yibin.gong@nxp.com>
  36 Reported-by: Jason Liu <jason.hui.liu@nxp.com>
  37 Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
  38 Fixes: 593034f1b908 ("MLK-16437: dma: fsl-edma-v3: fix kernel crash
  39 while edma interrupt trigger after channel disabled").
  40
  41 (cherry picked from commit e62e8707154f47e168fcfd148e97be4e2f991898)
  42 ---
  43  drivers/dma/fsl-edma-v3.c | 4 ++--
  44  1 file changed, 2 insertions(+), 2 deletions(-)
  45
  46 --- a/drivers/dma/fsl-edma-v3.c
  47 +++ b/drivers/dma/fsl-edma-v3.c
  48 @@ -692,7 +692,7 @@ static irqreturn_t fsl_edma3_tx_handler(
  49
  50         /* Ignore this interrupt since channel has been disabled already */
  51         if (!fsl_chan->edesc)
  52 -               return IRQ_HANDLED;
  53 +               goto irq_handled;
  54
  55         if (!fsl_chan->edesc->iscyclic) {
  56                 fsl_edma3_get_realcnt(fsl_chan);
  57 @@ -706,7 +706,7 @@ static irqreturn_t fsl_edma3_tx_handler(
  58
  59         if (!fsl_chan->edesc)
  60                 fsl_edma3_xfer_desc(fsl_chan);
  61 -
  62 +irq_handled:
  63         spin_unlock(&fsl_chan->vchan.lock);
  64
  65         return IRQ_HANDLED;