From 46c343673c6eae7909f644f9b67101ce14309670 Mon Sep 17 00:00:00 2001 From: Robin Gong Date: Tue, 19 Sep 2017 11:36:58 +0800 Subject: [PATCH] MLK-16482: dma: fsl-edma-v3: Fix RCU issue while playing Audio That's caused by commit 593034f1b908 ("MLK-16437: dma: fsl-edma-v3: fix kernel crash while edma interrupt trigger after channel disabled"). Because fsl_chan->vchan.lock will be hold always and trigger RCU report as below: 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 1571.5 [ 4642.698771] INFO: rcu_preempt detected stalls on CPUs/tasks: 1571.6 [ 4642.704443] 0-...: (1 GPs behind) idle=2c5/140000000000000/0 softirq=155373/155374 fqs=2541 1571.7 [ 4642.712967] (detected by 2, t=5252 jiffies, g=104259, c=104258, q=22) 1571.8 [ 4642.719501] Task dump for CPU 0: 1571.9 [ 4642.722724] aplay R running task 0 15723 15721 0x00000202 1571.10 [ 4642.729786] Call trace: 1571.11 [ 4642.732239] [] __switch_to+0x8c/0xa0 1571.12 [ 4642.737379] [] dma_chan_put+0x70/0xa0 1571.13 [ 4642.742603] [] dma_release_channel+0x34/0xa0 1571.14 [ 4642.748435] [] fsl_asrc_dma_hw_free+0x38/0x50 1571.15 [ 4642.754358] [] soc_pcm_hw_free+0x110/0x1a8 1571.16 [ 4642.760013] [] dpcm_fe_dai_hw_free+0x6c/0xe0 1571.17 [ 4642.765844] [] snd_pcm_common_ioctl1+0xb40/0xce0 1571.18 [ 4642.772028] [] snd_pcm_playback_ioctl1+0x1dc/0x310 1571.19 [ 4642.778378] [] snd_pcm_playback_ioctl+0x28/0x40 1571.20 [ 4642.784470] [] do_vfs_ioctl+0xa4/0x748 1571.21 [ 4642.789784] [] SyS_ioctl+0x8c/0xa0 1571.22 [ 4642.794745] [] __sys_trace_return+0x0/0x4 1571.23 [ 4705.718740] INFO: rcu_preempt detected stalls on CPUs/tasks: 1571.24 [ 4705.724420] 0-...: (1 GPs behind) idle=2c5/140000000000000/0 softirq=155373/155374 fqs=10407 1571.25 [ 4705.733030] (detected by 1, t=21010 jiffies, g=104259, c=104258, q=119) Signed-off-by: Robin Gong Reported-by: Jason Liu Reviewed-by: Daniel Baluta Fixes: 593034f1b908 ("MLK-16437: dma: fsl-edma-v3: fix kernel crash while edma interrupt trigger after channel disabled"). (cherry picked from commit e62e8707154f47e168fcfd148e97be4e2f991898) --- drivers/dma/fsl-edma-v3.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/dma/fsl-edma-v3.c +++ b/drivers/dma/fsl-edma-v3.c @@ -692,7 +692,7 @@ static irqreturn_t fsl_edma3_tx_handler( /* Ignore this interrupt since channel has been disabled already */ if (!fsl_chan->edesc) - return IRQ_HANDLED; + goto irq_handled; if (!fsl_chan->edesc->iscyclic) { fsl_edma3_get_realcnt(fsl_chan); @@ -706,7 +706,7 @@ static irqreturn_t fsl_edma3_tx_handler( if (!fsl_chan->edesc) fsl_edma3_xfer_desc(fsl_chan); - +irq_handled: spin_unlock(&fsl_chan->vchan.lock); return IRQ_HANDLED;