[PATCH] ASoC: soc-pcm: dpcm: Only allow playback/capture if supported
At the moment, PCM devices for DPCM are only created based on the dpcm_playback/capture parameters of the DAI link, without considering if the CPU/FE DAI is actually capable of playback/capture.
Normally the dpcm_playback/capture parameter should match the capabilities of the CPU DAI. However, there is no way to set that parameter from the device tree (e.g. with simple-audio-card or qcom sound cards). dpcm_playback/capture are always both set to 1.
This causes problems when the CPU DAI does only support playback or capture. Attemting to open that PCM device with an unsupported stream type then results in a null pointer dereference:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000128 Internal error: Oops: 96000044 [#1] PREEMPT SMP CPU: 3 PID: 1582 Comm: arecord Not tainted 5.7.0-rc1 pc : invalidate_paths_ep+0x30/0xe0 lr : snd_soc_dapm_dai_get_connected_widgets+0x170/0x1a8 Call trace: invalidate_paths_ep+0x30/0xe0 snd_soc_dapm_dai_get_connected_widgets+0x170/0x1a8 dpcm_path_get+0x38/0xd0 dpcm_fe_dai_open+0x70/0x920 snd_pcm_open_substream+0x564/0x840 snd_pcm_open+0xfc/0x228 snd_pcm_capture_open+0x4c/0x78 snd_open+0xac/0x1a8 ...
... because the DAI playback/capture_widget is not set in that case.
We could add checks there to fix the problem (maybe we should anyway), but much easier is to not expose the device as playback/capture in the first place. Attemting to use that device would always fail later anyway.
Add checks for snd_soc_dai_stream_valid() to the DPCM case to avoid exposing playback/capture if it is not supported.
Signed-off-by: Stephan Gerhold stephan@gerhold.net --- This can be reproduced with q6asm-dai with a device tree configuration like:
&q6asmdai { dai@0 { reg = <0>; direction = <Q6ASM_DAI_RX>; }; };
Then a simple "arecord output.wav" will result in the crash above, since it attempts to use that FE DAI for capture (even though it is limited to playback). --- sound/soc/soc-pcm.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 454735f8fa92..77a680da366f 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -2911,8 +2911,17 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num) int i;
if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm) { - playback = rtd->dai_link->dpcm_playback; - capture = rtd->dai_link->dpcm_capture; + cpu_dai = asoc_rtd_to_cpu(rtd, 0); + if (rtd->num_cpus > 1) { + dev_err(rtd->dev, + "DPCM doesn't support Multi CPU yet\n"); + return -EINVAL; + } + + playback = rtd->dai_link->dpcm_playback && + snd_soc_dai_stream_valid(cpu_dai, SNDRV_PCM_STREAM_PLAYBACK); + capture = rtd->dai_link->dpcm_capture && + snd_soc_dai_stream_valid(cpu_dai, SNDRV_PCM_STREAM_CAPTURE); } else { /* Adapt stream for codec2codec links */ int cpu_capture = rtd->dai_link->params ?
The patch
ASoC: soc-pcm: dpcm: Only allow playback/capture if supported
has been applied to the asoc tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
From 9b5db059366ae2087e07892b5fc108f81f4ec189 Mon Sep 17 00:00:00 2001
From: Stephan Gerhold stephan@gerhold.net Date: Wed, 15 Apr 2020 12:49:28 +0200 Subject: [PATCH] ASoC: soc-pcm: dpcm: Only allow playback/capture if supported
At the moment, PCM devices for DPCM are only created based on the dpcm_playback/capture parameters of the DAI link, without considering if the CPU/FE DAI is actually capable of playback/capture.
Normally the dpcm_playback/capture parameter should match the capabilities of the CPU DAI. However, there is no way to set that parameter from the device tree (e.g. with simple-audio-card or qcom sound cards). dpcm_playback/capture are always both set to 1.
This causes problems when the CPU DAI does only support playback or capture. Attemting to open that PCM device with an unsupported stream type then results in a null pointer dereference:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000128 Internal error: Oops: 96000044 [#1] PREEMPT SMP CPU: 3 PID: 1582 Comm: arecord Not tainted 5.7.0-rc1 pc : invalidate_paths_ep+0x30/0xe0 lr : snd_soc_dapm_dai_get_connected_widgets+0x170/0x1a8 Call trace: invalidate_paths_ep+0x30/0xe0 snd_soc_dapm_dai_get_connected_widgets+0x170/0x1a8 dpcm_path_get+0x38/0xd0 dpcm_fe_dai_open+0x70/0x920 snd_pcm_open_substream+0x564/0x840 snd_pcm_open+0xfc/0x228 snd_pcm_capture_open+0x4c/0x78 snd_open+0xac/0x1a8 ...
... because the DAI playback/capture_widget is not set in that case.
We could add checks there to fix the problem (maybe we should anyway), but much easier is to not expose the device as playback/capture in the first place. Attemting to use that device would always fail later anyway.
Add checks for snd_soc_dai_stream_valid() to the DPCM case to avoid exposing playback/capture if it is not supported.
Signed-off-by: Stephan Gerhold stephan@gerhold.net Link: https://lore.kernel.org/r/20200415104928.86091-1-stephan@gerhold.net Signed-off-by: Mark Brown broonie@kernel.org --- sound/soc/soc-pcm.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 289aebc15529..1f302de44052 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -2911,8 +2911,17 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num) int i;
if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm) { - playback = rtd->dai_link->dpcm_playback; - capture = rtd->dai_link->dpcm_capture; + cpu_dai = asoc_rtd_to_cpu(rtd, 0); + if (rtd->num_cpus > 1) { + dev_err(rtd->dev, + "DPCM doesn't support Multi CPU yet\n"); + return -EINVAL; + } + + playback = rtd->dai_link->dpcm_playback && + snd_soc_dai_stream_valid(cpu_dai, SNDRV_PCM_STREAM_PLAYBACK); + capture = rtd->dai_link->dpcm_capture && + snd_soc_dai_stream_valid(cpu_dai, SNDRV_PCM_STREAM_CAPTURE); } else { /* Adapt stream for codec2codec links */ int cpu_capture = rtd->dai_link->params ?
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 454735f8fa92..77a680da366f 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -2911,8 +2911,17 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num) int i;
if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm) {
playback = rtd->dai_link->dpcm_playback;capture = rtd->dai_link->dpcm_capture;
cpu_dai = asoc_rtd_to_cpu(rtd, 0);if (rtd->num_cpus > 1) {dev_err(rtd->dev,"DPCM doesn't support Multi CPU yet\n");return -EINVAL;}playback = rtd->dai_link->dpcm_playback &&snd_soc_dai_stream_valid(cpu_dai, SNDRV_PCM_STREAM_PLAYBACK);capture = rtd->dai_link->dpcm_capture &&snd_soc_dai_stream_valid(cpu_dai, SNDRV_PCM_STREAM_CAPTURE);
This commit introduces major regressions with SOF on CherryTrail and Broadwell:
[ 25.705750] SSP2-Codec: ASoC: no backend playback stream [ 27.923378] SSP2-Codec: ASoC: no users playback at close - state
it's likely due to the check for min_channels > 0 in snd_soc_dai_stream_valid(), which wasn't a requirement before.
We are testing a fix [1] but other users of DPCM might be impacted.
Mark, this commit is on your for-5.7 branch but not on for-next? Not sure which SHA1 to use for the Fixes: tag
[1] https://github.com/thesofproject/linux/pull/2018/commits/4fa10638dca8aad7a32...
On Thu, Apr 16, 2020 at 03:51:23PM -0500, Pierre-Louis Bossart wrote:
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 454735f8fa92..77a680da366f 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -2911,8 +2911,17 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num) int i; if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm) {
playback = rtd->dai_link->dpcm_playback;capture = rtd->dai_link->dpcm_capture;
cpu_dai = asoc_rtd_to_cpu(rtd, 0);if (rtd->num_cpus > 1) {dev_err(rtd->dev,"DPCM doesn't support Multi CPU yet\n");return -EINVAL;}playback = rtd->dai_link->dpcm_playback &&snd_soc_dai_stream_valid(cpu_dai, SNDRV_PCM_STREAM_PLAYBACK);capture = rtd->dai_link->dpcm_capture &&snd_soc_dai_stream_valid(cpu_dai, SNDRV_PCM_STREAM_CAPTURE);This commit introduces major regressions with SOF on CherryTrail and Broadwell:
[ 25.705750] SSP2-Codec: ASoC: no backend playback stream [ 27.923378] SSP2-Codec: ASoC: no users playback at close - stateit's likely due to the check for min_channels > 0 in snd_soc_dai_stream_valid(), which wasn't a requirement before.
We are testing a fix [1] but other users of DPCM might be impacted.
Indeed, I actually ran into a similar problem myself for q6afe-dai: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git/commit/?h=...
As mentioned in that commit message it was already broken on 5.7-rc1 for me, because of commit 0e9cf4c452ad ("ASoC: pcm: check if cpu-dai supports a given stream"). [2]
With this commit it's more visible at least, you get a proper error instead of silently not calling hw_params() for example. :)
[2]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
Mark, this commit is on your for-5.7 branch but not on for-next? Not sure which SHA1 to use for the Fixes: tag
[1] https://github.com/thesofproject/linux/pull/2018/commits/4fa10638dca8aad7a32...
On Thu, Apr 16, 2020 at 03:51:23PM -0500, Pierre-Louis Bossart wrote:
Mark, this commit is on your for-5.7 branch but not on for-next? Not sure which SHA1 to use for the Fixes: tag
The commit you're fixing should be the commit you're fixing regardless of which branch it is on.
participants (3)
-
Mark Brown -
Pierre-Louis Bossart -
Stephan Gerhold