| From 316fa9e09ad76e095b9d7e9350c628b918370a22 Mon Sep 17 00:00:00 2001 |
| From: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> |
| Date: Thu, 18 Feb 2016 15:47:13 +0000 |
| Subject: ASoC: samsung: Use IRQ safe spin lock calls |
| |
| From: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> |
| |
| commit 316fa9e09ad76e095b9d7e9350c628b918370a22 upstream. |
| |
| 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> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| sound/soc/samsung/i2s.c | 21 ++++++++++++--------- |
| 1 file changed, 12 insertions(+), 9 deletions(-) |
| |
| --- a/sound/soc/samsung/i2s.c |
| +++ b/sound/soc/samsung/i2s.c |
| @@ -480,10 +480,11 @@ static int i2s_set_sysclk(struct snd_soc |
| 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: |
| @@ -574,11 +575,11 @@ static int i2s_set_sysclk(struct snd_soc |
| 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; |
| } |
| @@ -589,6 +590,7 @@ static int i2s_set_fmt(struct snd_soc_da |
| 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; |
| @@ -648,7 +650,7 @@ static int i2s_set_fmt(struct snd_soc_da |
| 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 |
| @@ -656,7 +658,7 @@ static int i2s_set_fmt(struct snd_soc_da |
| */ |
| 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; |
| @@ -665,7 +667,7 @@ static int i2s_set_fmt(struct snd_soc_da |
| 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; |
| } |
| @@ -675,6 +677,7 @@ static int i2s_hw_params(struct snd_pcm_ |
| { |
| 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); |
| @@ -743,11 +746,11 @@ static int i2s_hw_params(struct snd_pcm_ |
| 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); |
| |