[PATCH 4.9 126/206] ASoC: samsung: i2s: Fixup last IRQ unsafe spin lock call

From: Greg Kroah-Hartman
Date: Tue Jan 10 2017 - 09:31:29 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>

commit 5faf071d08ddd1c1be66deaa93a09ccf43f5b538 upstream.

Unfortunately, I seem to have missed a case where an IRQ safe spinlock was
required, in samsung_i2s_dai_remove, when I fixed up the other calls in
this patch:

316fa9e09ad7 ("ASoC: samsung: Use IRQ safe spin lock calls")

This causes a lockdep warning when unbinding and rebinding the audio card:

[ 104.357664] CPU0 CPU1
[ 104.362174] ---- ----
[ 104.366692] lock(&(&pri_dai->spinlock)->rlock);
[ 104.371372] local_irq_disable();
[ 104.377283] lock(&(&substream->self_group.lock)->rlock);
[ 104.385259] lock(&(&pri_dai->spinlock)->rlock);
[ 104.392469] <Interrupt>
[ 104.395072] lock(&(&substream->self_group.lock)->rlock);
[ 104.400710]
[ 104.400710] *** DEADLOCK ***

Fixes: ce8bcdbb61d9 ("ASoC: samsung: i2s: Protect more registers with a spinlock")
Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
sound/soc/samsung/i2s.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/sound/soc/samsung/i2s.c
+++ b/sound/soc/samsung/i2s.c
@@ -1029,12 +1029,13 @@ static int samsung_i2s_dai_probe(struct
static int samsung_i2s_dai_remove(struct snd_soc_dai *dai)
{
struct i2s_dai *i2s = snd_soc_dai_get_drvdata(dai);
+ unsigned long flags;

if (!is_secondary(i2s)) {
if (i2s->quirks & QUIRK_NEED_RSTCLR) {
- spin_lock(i2s->lock);
+ spin_lock_irqsave(i2s->lock, flags);
writel(0, i2s->addr + I2SCON);
- spin_unlock(i2s->lock);
+ spin_unlock_irqrestore(i2s->lock, flags);
}
}