RE: [PATCH RFC] ASoC: sh: rcar: dma: : use proper DMAENGINE API for termination

[Yoshihiro Shimoda]

Hi Wolfram-san,

> From: Wolfram Sang, Sent: Wednesday, June 23, 2021 7:06 PM
> 
> dmaengine_terminate_all() is deprecated in favor of explicitly saying if
> it should be sync or async. Here, we want dmaengine_terminate_sync()
> because there is no other synchronization code in the driver to handle
> an async case.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> ---
> 
> Morimoto-san, can you please double check if this works. I don't know
> this driver very well. Thank you!
> 
>  sound/soc/sh/rcar/dma.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/sound/soc/sh/rcar/dma.c b/sound/soc/sh/rcar/dma.c
> index 95aa26d62e4f..d1b46057df9e 100644
> --- a/sound/soc/sh/rcar/dma.c
> +++ b/sound/soc/sh/rcar/dma.c
> @@ -101,7 +101,7 @@ static int rsnd_dmaen_stop(struct rsnd_mod *mod,
>  	struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);
> 
>  	if (dmaen->chan)
> -		dmaengine_terminate_all(dmaen->chan);
> +		dmaengine_terminate_sync(dmaen->chan);
> 
>  	return 0;
>  }

I'm afraid but, our test team detected an issue [1] on v5.15-rc2 with m3ulcb and ebusu.
# Our test team doesn't test this on salvator-xs yet...
I asked Morimoto-san locally, and he guess that using dmaengine_terminate_async() instead
of dmaengine_terminate_sync() could be resolved. But, what do you think?

Best regards,
Yoshihiro Shimoda

----
[1]
root@m3ulcb:~# amixer set 'DVC Out Mute' off
Simple mixer control 'DVC Out Mute',0
  Capabilities: pswitch
  Playback channels: Front Left - Front Right
  Mono:
  Front Left: Playback [off]
  F on v5.15-rc2ront Right: Playback [off]
root@m3ulcb:~# 
root@m3ulcb:~# amixer set 'DVC In Mute' off
Simple mixer control 'DVC In Mute',0
  Capabilities: pswitch
  Playback channels: Front Left - Front Right
  Mono:
  Front Left: Playback [off]
  Front Right: Playback [off]
root@m3ulcb:~# 
root@m3ulcb:~# amixer set "DVC Out" 20%
Simple mixer control 'DVC Out',0
  Capabilities: pvolume
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 8388607
  Mono:
  Front Left: Playback 1677722 [20%]
  Front Right: Playback 1677722 [20%]
root@m3ulcb:~# 
root@m3ulcb:~# amixer set "DVC In" 50%
Simple mixer control 'DVC In',0
  Capabilities: cvolume
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 8388607
  Front Left: Capture 4194304 [50%]
  Front Right: Capture 4194304 [50%]
root@m3ulcb:~# 
root@m3ulcb:~# amixer set "Digital Playback Volume1" 85%
Simple mixer control 'Digital Playback Volume1',0
  Capabilities: volume
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 255
  Front Left: 217 [85%]
  Front Right: 217 [85%]
root@m3ulcb:~# 
root@m3ulcb:~# aplay  ~/audio.wav
Playing WAVE '/home/root/audio.wav' : Signed 32 bit Little Endian, Rate 44100 Hz, Stereo
[  161.583393] BUG: scheduling while atomic: irq/128-ec70000/238/0x00000003
[  161.590358] 2 locks held by irq/128-ec70000/238:
[  161.595053]  #0: ffff000442670508 (&group->lock){....}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0x34/0x40
[  161.604723]  #1: ffff000442e3aea0 (&priv->lock#3){....}-{2:2}, at: rsnd_soc_dai_trigger+0x64/0x7c8
[  161.613853] irq event stamp: 48292
[  161.617310] hardirqs last  enabled at (48291): [<ffff800010ca1d5c>] _raw_spin_unlock_irq+0x3c/0x88
[  161.626418] hardirqs last disabled at (48292): [<ffff800010ca1968>] _raw_spin_lock_irqsave+0xb0/0xc0
[  161.635699] softirqs last  enabled at (47268): [<ffff800010010464>] _stext+0x464/0x5d8
[  161.643746] softirqs last disabled at (47263): [<ffff80001008f738>] irq_exit+0x198/0x1b8
[  161.651975] CPU: 0 PID: 238 Comm: irq/128-ec70000 Not tainted 5.15.0-rc2-arm64-renesas #1
[  161.660287] Hardware name: Renesas M3ULCB Kingfisher board based on r8a77961 (DT)
[  161.667888] Call trace:
[  161.670376]  dump_backtrace+0x0/0x188
[  161.674103]  show_stack+0x14/0x20
[  161.677474]  dump_stack_lvl+0x88/0xb0
[  161.681201]  dump_stack+0x14/0x2c
[  161.684571]  __schedule_bug+0x7c/0x90
[  161.688298]  __schedule+0x8bc/0x960
[  161.691848]  schedule+0x6c/0xf8
[  161.695043]  synchronize_irq+0x74/0xa8
[  161.698858]  rcar_dmac_device_synchronize+0x10/0x18
[  161.703820]  rsnd_dmaen_stop+0x40/0x50
[  161.707633]  rsnd_soc_dai_trigger+0x640/0x7c8
[  161.712061]  soc_dai_trigger+0x3c/0x80
[  161.715875]  snd_soc_pcm_dai_trigger+0xc0/0x168
[  161.720481]  soc_pcm_trigger+0x144/0x1b8
[  161.724472]  snd_pcm_do_stop+0x64/0x80
[  161.728284]  snd_pcm_action_single+0x44/0x98
[  161.732625]  snd_pcm_drain_done+0x20/0x28
[  161.736701]  snd_pcm_update_state+0xf4/0x128
[  161.741043]  snd_pcm_update_hw_ptr0+0x22c/0x3b0
[  161.745649]  snd_pcm_period_elapsed_under_stream_lock+0x64/0x88
[  161.751665]  snd_pcm_period_elapsed+0x24/0x40
[  161.756092]  rsnd_dai_period_elapsed+0x10/0x18
[  161.760611]  __rsnd_dmaen_complete+0x30/0x40
[  161.764953]  rsnd_mod_interrupt+0x90/0xe0
[  161.769029]  rsnd_dmaen_complete+0x14/0x20
[  161.773194]  rcar_dmac_isr_channel_thread+0x188/0x198
[  161.778328]  irq_thread_fn+0x28/0x88
[  161.781963]  irq_thread+0x158/0x1c8
[  161.785510]  kthread+0x14c/0x158
[  161.788794]  ret_from_fork+0x10/0x20
[  199.053832] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[  199.060273] rcu: 	2-...0: (0 ticks this GP) idle=891/1/0x4000000000000000 softirq=3570/3570 fqs=3093 
[  199.070267] 	(detected by 0, t=6505 jiffies, g=8077, q=6)
[  199.075940] Task dump for CPU 2:
[  199.079339] task:aplay           state:R  running task     stack:    0 pid:  513 ppid:   502 flags:0x00000202
[  199.089753] Call trace:
[  199.092333]  __switch_to+0x12c/0x180
[  199.096113]  0x3ec50aaa435c9700
[  199.099421]  snd_pcm_stream_lock_irq+0x30/0x38