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authorCharles Keepax2016-02-18 16:47:13 +0100
committerMark Brown2016-02-19 16:29:19 +0100
commit316fa9e09ad76e095b9d7e9350c628b918370a22 (patch)
treecf71c3a2f24e32ac49e26039eaa5a3fa55cfe17a
parentLinux 4.5-rc1 (diff)
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ASoC: samsung: Use IRQ safe spin lock calls
Lockdep warns of a potential lock inversion, i2s->lock is held numerous times whilst we are under the substream lock (snd_pcm_stream_lock). If we use the IRQ unsafe spin lock calls, you can also end up locking snd_pcm_stream_lock whilst under i2s->lock (if an IRQ happens whilst we are holding i2s->lock). This could result in deadlock. [ 18.147001] CPU0 CPU1 [ 18.151509] ---- ---- [ 18.156022] lock(&(&pri_dai->spinlock)->rlock); [ 18.160701] local_irq_disable(); [ 18.166622] lock(&(&substream->self_group.lock)->rlock); [ 18.174595] lock(&(&pri_dai->spinlock)->rlock); [ 18.181806] <Interrupt> [ 18.184408] lock(&(&substream->self_group.lock)->rlock); [ 18.190045] [ 18.190045] *** DEADLOCK *** This patch changes to using the irq safe spinlock calls, to avoid this issue. Fixes: ce8bcdbb61d9 ("ASoC: samsung: i2s: Protect more registers with a spinlock") Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Tested-by: Anand Moon <linux.amoon@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
-rw-r--r--sound/soc/samsung/i2s.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/sound/soc/samsung/i2s.c b/sound/soc/samsung/i2s.c
index 84d9e77c0fbe..70a2559b63f9 100644
--- a/sound/soc/samsung/i2s.c
+++ b/sound/soc/samsung/i2s.c
@@ -481,10 +481,11 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
unsigned int cdcon_mask = 1 << i2s_regs->cdclkcon_off;
unsigned int rsrc_mask = 1 << i2s_regs->rclksrc_off;
u32 mod, mask, val = 0;
+ unsigned long flags;
- spin_lock(i2s->lock);
+ spin_lock_irqsave(i2s->lock, flags);
mod = readl(i2s->addr + I2SMOD);
- spin_unlock(i2s->lock);
+ spin_unlock_irqrestore(i2s->lock, flags);
switch (clk_id) {
case SAMSUNG_I2S_OPCLK:
@@ -575,11 +576,11 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
return -EINVAL;
}
- spin_lock(i2s->lock);
+ spin_lock_irqsave(i2s->lock, flags);
mod = readl(i2s->addr + I2SMOD);
mod = (mod & ~mask) | val;
writel(mod, i2s->addr + I2SMOD);
- spin_unlock(i2s->lock);
+ spin_unlock_irqrestore(i2s->lock, flags);
return 0;
}
@@ -590,6 +591,7 @@ static int i2s_set_fmt(struct snd_soc_dai *dai,
struct i2s_dai *i2s = to_info(dai);
int lrp_shift, sdf_shift, sdf_mask, lrp_rlow, mod_slave;
u32 mod, tmp = 0;
+ unsigned long flags;
lrp_shift = i2s->variant_regs->lrp_off;
sdf_shift = i2s->variant_regs->sdf_off;
@@ -649,7 +651,7 @@ static int i2s_set_fmt(struct snd_soc_dai *dai,
return -EINVAL;
}
- spin_lock(i2s->lock);
+ spin_lock_irqsave(i2s->lock, flags);
mod = readl(i2s->addr + I2SMOD);
/*
* Don't change the I2S mode if any controller is active on this
@@ -657,7 +659,7 @@ static int i2s_set_fmt(struct snd_soc_dai *dai,
*/
if (any_active(i2s) &&
((mod & (sdf_mask | lrp_rlow | mod_slave)) != tmp)) {
- spin_unlock(i2s->lock);
+ spin_unlock_irqrestore(i2s->lock, flags);
dev_err(&i2s->pdev->dev,
"%s:%d Other DAI busy\n", __func__, __LINE__);
return -EAGAIN;
@@ -666,7 +668,7 @@ static int i2s_set_fmt(struct snd_soc_dai *dai,
mod &= ~(sdf_mask | lrp_rlow | mod_slave);
mod |= tmp;
writel(mod, i2s->addr + I2SMOD);
- spin_unlock(i2s->lock);
+ spin_unlock_irqrestore(i2s->lock, flags);
return 0;
}
@@ -676,6 +678,7 @@ static int i2s_hw_params(struct snd_pcm_substream *substream,
{
struct i2s_dai *i2s = to_info(dai);
u32 mod, mask = 0, val = 0;
+ unsigned long flags;
if (!is_secondary(i2s))
mask |= (MOD_DC2_EN | MOD_DC1_EN);
@@ -744,11 +747,11 @@ static int i2s_hw_params(struct snd_pcm_substream *substream,
return -EINVAL;
}
- spin_lock(i2s->lock);
+ spin_lock_irqsave(i2s->lock, flags);
mod = readl(i2s->addr + I2SMOD);
mod = (mod & ~mask) | val;
writel(mod, i2s->addr + I2SMOD);
- spin_unlock(i2s->lock);
+ spin_unlock_irqrestore(i2s->lock, flags);
samsung_asoc_init_dma_data(dai, &i2s->dma_playback, &i2s->dma_capture);