On Tuesday, March 31, 2020 10:55 AM, Gyeongtaek Lee wrote:
Hi,
On 30-03-20, 17:17, Vinod Koul wrote:
Hello,
On 30-03-20, 20:01, ̰ wrote:
snd_soc_runtime_activate() and snd_soc_runtime_deactivate() require locked pcm_mutex.
Signed-off-by: Gyeongtaek Lee gt82.lee@samsung.com
sound/soc/soc-compress.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c index 392a1c5b15d3..42d416ac7e9b 100644 --- a/sound/soc/soc-compress.c +++ b/sound/soc/soc-compress.c @@ -207,7 +207,9 @@ static int soc_compr_open_fe(struct snd_compr_stream *cstream) fe->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN; fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;
- mutex_lock_nested(&fe->pcm_mutex, fe->pcm_subclass); snd_soc_runtime_activate(fe, stream);
- mutex_unlock(&fe->pcm_mutex);
Can you please explain why you need the lock here, as
mutex_unlock(&fe->card->mutex);
we already have a lock here..
@@ -285,7 +287,9 @@ static int soc_compr_free_fe(struct snd_compr_stream *cstream) else stream = SNDRV_PCM_STREAM_CAPTURE;
- mutex_lock_nested(&fe->pcm_mutex, fe->pcm_subclass); snd_soc_runtime_deactivate(fe, stream);
- mutex_unlock(&fe->pcm_mutex);
And this instance is also using fe->card->mutex.. so I think double lock may not serve any purpose here..
Can you explain why we need the extra lock?
You are right. The mutex_lock with fe->pcm_mutex has no purpose. It just removes lockdep warning like the below <4>[ 1437.857354] [5: cplay:11547] ------------[ cut here ]------------ <4>[ 1437.857463] [5: cplay:11547] WARNING: CPU: 5 PID: 11547 at sound/soc/soc-pcm.c:99 snd_soc_runtime_deactivate+0x88/0x140 <4>[ 1437.857498] [5: cplay:11547] Modules linked in: <4>[ 1437.857557] [5: cplay:11547] CPU: 5 PID: 11547 Comm: cplay Tainted: G S W 4.19.65-00198-ge6c3a8b64f3d-dirty #146 <4>[ 1437.857590] [5: cplay:11547] Hardware name: Samsung xxx board based on xxx (DT) <4>[ 1437.857620] [5: cplay:11547] Call trace: <4>[ 1437.857662] [5: cplay:11547] [<ffffff800808d598>] dump_backtrace+0x0/0x404 <4>[ 1437.857704] [5: cplay:11547] [<ffffff800808d9b0>] show_stack+0x14/0x1c <4>[ 1437.857745] [5: cplay:11547] [<ffffff8008c5dc24>] dump_stack+0xa0/0xd8 <4>[ 1437.857784] [5: cplay:11547] [<ffffff80080a4b28>] __warn+0xcc/0x12c <4>[ 1437.857821] [5: cplay:11547] [<ffffff8008c5cd78>] report_bug+0x78/0xcc <4>[ 1437.857857] [5: cplay:11547] [<ffffff800808e5c0>] bug_handler+0x2c/0x88 <4>[ 1437.857895] [5: cplay:11547] [<ffffff8008085510>] brk_handler+0x88/0xc8 <4>[ 1437.857930] [5: cplay:11547] [<ffffff8008080f0c>] do_debug_exception+0x108/0x194 <4>[ 1437.857968] [5: cplay:11547] Exception stack(0xffffff8028b0b960 to 0xffffff8028b0baa0) <4>[ 1437.858002] [5: cplay:11547] b960: 0000000000000024 ffffff8008e28a97 ffffffc975bb40a0 ffffff8028b0b748 <4>[ 1437.858035] [5: cplay:11547] b980: 0000000000000080 0000000000000000 ffffff8008129638 0000000000000000 <4>[ 1437.858066] [5: cplay:11547] b9a0: e0b1dc92eba18f00 e0b1dc92eba18f00 0000000000000003 0000000000000000 <4>[ 1437.858098] [5: cplay:11547] b9c0: 0000000000240022 0000000000000004 ffffff8009b2f420 00000000fffffff5 <4>[ 1437.858130] [5: cplay:11547] b9e0: ffffff8008c6baac 000000000000002c 00000000000000b0 ffffffc9673c1e80 <4>[ 1437.858161] [5: cplay:11547] ba00: 0000000000000000 ffffffc8190e6100 0000000000000000 ffffffc95c262e88 <4>[ 1437.858193] [5: cplay:11547] ba20: 0000000000000008 ffffffc8ec3050d0 ffffffc8fb81a4d0 0000000000000004 <4>[ 1437.858224] [5: cplay:11547] ba40: 0000000000000009 ffffff8028b0bac0 ffffff8008a895c8 ffffff8028b0baa0 <4>[ 1437.858256] [5: cplay:11547] ba60: ffffff8008a895c8 0000000060400005 ffffff8028b0ba48 ffffff800811d7b4 <4>[ 1437.858287] [5: cplay:11547] ba80: 0000007fffffffff e0b1dc92eba18f00 ffffff8028b0bac0 ffffff8008a895c8 <4>[ 1437.858318] [5: cplay:11547] [<ffffff8008082b18>] el1_dbg+0x18/0x78 <4>[ 1437.858355] [5: cplay:11547] [<ffffff8008a895c8>] snd_soc_runtime_deactivate+0x88/0x140
from here void snd_soc_runtime_activate(struct snd_soc_pcm_runtime *rtd, int stream) { struct snd_soc_dai *cpu_dai = rtd->cpu_dai; int i;
lockdep_assert_held(&rtd->pcm_mutex);
and here. void snd_soc_runtime_deactivate(struct snd_soc_pcm_runtime *rtd, int stream) { struct snd_soc_dai *cpu_dai = rtd->cpu_dai; int i;
lockdep_assert_held(&rtd->pcm_mutex);
Approach method of this patch is too simple but, I think that simple approach can be used until the nicer patch arrives.
Thank you for your fast review.
Thanks
~Vinod
Hi,
Could you review my answer and patch and give me a comment? If you have any suggestion, just let me know it.
Thanks
Gyeongtaek