ASoC: Add locking in DAPM widget power update.
While playback and capture is done concurrently the dapm widget
data is accessed parallelly which results in data corruption and
kernel panic. Fix this problem by serializing the stream event
operation by adding lock
dapm_seq_run will invoke dapm power sequence for pre-sorted list
of widgets to be powered up. Kernel panic issue is observed
during stability runs with the above sequence caused by null
pointer dereference in dapm_seq_run_coalesced. Fix kernel panic
issue by checking for valid snd_soc_dapm_context pointer in
dapm_seq_run before invoking dapm_seq_run_coalesced
Widget list in dapm is getting corrupted during concurrent
use cases where dapm_power_widget is accessed. This corruption
is resulting in kernel crash in dapm. Fix the issue by adding
protection in dapm_power_widgets API.
CRs-Fixed: 388785
Signed-off-by: Sriranjan Srikantam <cssrika@codeaurora.org>
(cherry picked from commit fd7f1ad52d7f848073c90c6a79c1d9fce1ff4ee5)
(cherry picked from commit 343e95447979b2b5592b9523c4abc8422f149487)
Change-Id: I1c91d4a55d0918e36315b9afce367e2f453ea9a7
Signed-off-by: Sudhir Sharma <sudsha@codeaurora.org>
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index 729142f..5ac643416 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -1290,7 +1290,7 @@
/* Do we need to apply any queued changes? */
if (sort[w->id] != cur_sort || w->reg != cur_reg ||
w->dapm != cur_dapm || w->subseq != cur_subseq) {
- if (!list_empty(&pending))
+ if (cur_dapm && !list_empty(&pending))
dapm_seq_run_coalesced(cur_dapm, &pending);
if (cur_dapm && cur_dapm->seq_notifier) {
@@ -1350,7 +1350,7 @@
"Failed to apply widget power: %d\n", ret);
}
- if (!list_empty(&pending))
+ if (cur_dapm && !list_empty(&pending))
dapm_seq_run_coalesced(cur_dapm, &pending);
if (cur_dapm && cur_dapm->seq_notifier) {
@@ -1567,6 +1567,8 @@
trace_snd_soc_dapm_start(card);
+ mutex_lock(&card->dapm_power_mutex);
+
list_for_each_entry(d, &card->dapm_list, list) {
if (d->n_widgets || d->codec == NULL) {
if (d->idle_bias_off)
@@ -1682,6 +1684,8 @@
"DAPM sequencing finished, waiting %dms\n", card->pop_time);
pop_wait(card->pop_time);
+ mutex_unlock(&card->dapm_power_mutex);
+
trace_snd_soc_dapm_done(card);
return 0;
@@ -3092,9 +3096,9 @@
if (stream == NULL)
return 0;
- //mutex_lock(&codec->mutex);
+ mutex_lock(&codec->mutex);
soc_dapm_stream_event(&codec->dapm, stream, event);
- //mutex_unlock(&codec->mutex);
+ mutex_unlock(&codec->mutex);
return 0;
}