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.
This change also squashes the below changes-
(1)
ASoC: dapm: fix race condition in dapm
Dirty widget list can be accessed by multiple paths
in dapm framework. Dirty list is protected by dapm mutex.
Since dapm_force_enable_pin function accesses the dirty
list, protect it using the dapm mutex.
(2)
soc-dapm: Fix double mutex lock
dapm_mutex lock is acquired from soc_dapm_force_enable_pin_unlocked
function which will cause double lock because the same mutex is
acquired in soc_dapm_force_enable_pin(). Fix this issue by removing
dapm_mutex acquire from soc_dapm_force_enable_pin_unlocked function.
CRs-Fixed: 388785
Change-Id: I49d19860277726cf3152e104ab40627fd56c021c
Signed-off-by: Sriranjan Srikantam <cssrika@codeaurora.org>
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index 3bbe32e..a1d583c 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -1515,7 +1515,7 @@
/* 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(card, &pending);
if (cur_dapm && cur_dapm->seq_notifier) {
@@ -1578,7 +1578,7 @@
"ASoC: Failed to apply widget power: %d\n", ret);
}
- if (!list_empty(&pending))
+ if (cur_dapm && !list_empty(&pending))
dapm_seq_run_coalesced(card, &pending);
if (cur_dapm && cur_dapm->seq_notifier) {
@@ -1814,6 +1814,7 @@
lockdep_assert_held(&card->dapm_mutex);
trace_snd_soc_dapm_start(card);
+ mutex_lock(&card->dapm_power_mutex);
list_for_each_entry(d, &card->dapm_list, list) {
if (dapm_idle_bias_off(d))
@@ -1932,6 +1933,7 @@
pop_dbg(card->dev, card->pop_time,
"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);