On 10/13/2021 8:00 PM, Pierre-Louis Bossart wrote:
The D in DPCM stands for 'dynamic', which means that connections between FE and BE can evolve.
Commit a97648697790 ("ASoC: dpcm: prevent snd_soc_dpcm use after free") started to protect some of the for_each_dpcm_be() loops, but there are still many cases that were not modified.
This patch adds protection for all the remaining loops, with the notable exception of the dpcm_be_dai_trigger(), where the lock is already taken at a higher level, e.g. in snd_pcm_period_elapsed().
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
sound/soc/soc-pcm.c | 86 ++++++++++++++++++++------------------------- 1 file changed, 39 insertions(+), 47 deletions(-)
After this, once I load sound card there are warning prints and failure:
[ 71.224324] WARNING: CPU: 3 PID: 574 at drivers/firmware/tegra/bpmp.c:362 tegra_bpmp_transfer+0x2d0/0x328 [ 71.238032] ---[ end trace 88d978f78a82134f ]--- [ 71.243033] WARNING: CPU: 3 PID: 574 at drivers/firmware/tegra/bpmp.c:362 tegra_bpmp_transfer+0x2d0/0x328 [ 71.257022] ---[ end trace 88d978f78a821350 ]--- [ 71.261965] tegra-audio-graph-card sound: Can't set plla rate for 270950400, err: -22 ...
This happens because, now the atomicity is propagated to BE callbacks where the clock settings are done in hw_param(). On Tegra, the clock APIs are served by BPMP and warning is seen because of below.
int tegra_bpmp_transfer() {
=> if (WARN_ON(irqs_disabled())) return -EPERM;
...
}
This results in hw_param() failure and all tests fail at my end.