[alsa-devel] [PATCH/RFC 10/14] ASoC: samsung: i2s: Protect access to more registers with a spinlock
Sylwester Nawrocki
s.nawrocki at samsung.com
Thu Dec 11 18:45:48 CET 2014
It seems this driver hasn't been updated for SMP, as local_irq_save/
local_irq_restore doesn't provide proper protection of read/modify/
write of the device's registers on such systems. Introduce a spinlock
serializing access to the registers, it will be helpful later when
I2SMOD, I2SPSR registers are made also accessible through the clk API.
Possibly some changes within this patch are not required, I'm not
confident what exactly needs to be serialized in the driver and what
is already taken care for in the ASoC core. At least I tried to cover
the I2SMOD, I2SPSR registers. Since the I2S register region is common
for 2 DAIs I suspect the serialization here might need again a careful
review.
Signed-off-by: Sylwester Nawrocki <s.nawrocki at samsung.com>
---
sound/soc/samsung/i2s.c | 81 +++++++++++++++++++++++++++++------------------
1 file changed, 51 insertions(+), 30 deletions(-)
diff --git a/sound/soc/samsung/i2s.c b/sound/soc/samsung/i2s.c
index e8e0107..825138b 100644
--- a/sound/soc/samsung/i2s.c
+++ b/sound/soc/samsung/i2s.c
@@ -472,17 +472,22 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
{
struct i2s_dai *i2s = to_info(dai);
struct i2s_dai *other = get_other_dai(i2s);
- u32 mod = readl(i2s->addr + I2SMOD);
const struct samsung_i2s_variant_regs *i2s_regs = i2s->variant_regs;
unsigned int cdcon_mask = 1 << i2s_regs->cdclkcon_off;
unsigned int rsrc_mask = 1 << i2s_regs->rclksrc_off;
+ u32 mod, mask, val = 0;
+
+ spin_lock(i2s->lock);
+ mod = readl(i2s->addr + I2SMOD);
+ spin_unlock(i2s->lock);
switch (clk_id) {
case SAMSUNG_I2S_OPCLK:
- mod &= ~MOD_OPCLK_MASK;
- mod |= dir;
+ mask = MOD_OPCLK_MASK;
+ val = dir;
break;
case SAMSUNG_I2S_CDCLK:
+ mask = 1 << i2s_regs->cdclkcon_off;
/* Shouldn't matter in GATING(CLOCK_IN) mode */
if (dir == SND_SOC_CLOCK_IN)
rfs = 0;
@@ -499,15 +504,15 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
}
if (dir == SND_SOC_CLOCK_IN)
- mod |= 1 << i2s_regs->cdclkcon_off;
- else
- mod &= ~(1 << i2s_regs->cdclkcon_off);
+ val = 1 << i2s_regs->cdclkcon_off;
i2s->rfs = rfs;
break;
case SAMSUNG_I2S_RCLKSRC_0: /* clock corrsponding to IISMOD[10] := 0 */
case SAMSUNG_I2S_RCLKSRC_1: /* clock corrsponding to IISMOD[10] := 1 */
+ mask = 1 << i2s_regs->rclksrc_off;
+
if ((i2s->quirks & QUIRK_NO_MUXPSR)
|| (clk_id == SAMSUNG_I2S_RCLKSRC_0))
clk_id = 0;
@@ -557,18 +562,19 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
return 0;
}
- if (clk_id == 0)
- mod &= ~(1 << i2s_regs->rclksrc_off);
- else
- mod |= 1 << i2s_regs->rclksrc_off;
-
+ if (clk_id == 1)
+ val = 1 << i2s_regs->rclksrc_off;
break;
default:
dev_err(&i2s->pdev->dev, "We don't serve that!\n");
return -EINVAL;
}
+ spin_lock(i2s->lock);
+ mod = readl(i2s->addr + I2SMOD);
+ mod = (mod & ~mask) | val;
writel(mod, i2s->addr + I2SMOD);
+ spin_unlock(i2s->lock);
return 0;
}
@@ -577,9 +583,8 @@ static int i2s_set_fmt(struct snd_soc_dai *dai,
unsigned int fmt)
{
struct i2s_dai *i2s = to_info(dai);
- u32 mod = readl(i2s->addr + I2SMOD);
int lrp_shift, sdf_shift, sdf_mask, lrp_rlow, mod_slave;
- u32 tmp = 0;
+ u32 mod, tmp = 0;
lrp_shift = i2s->variant_regs->lrp_off;
sdf_shift = i2s->variant_regs->sdf_off;
@@ -639,12 +644,15 @@ static int i2s_set_fmt(struct snd_soc_dai *dai,
return -EINVAL;
}
+ spin_lock(i2s->lock);
+ mod = readl(i2s->addr + I2SMOD);
/*
* Don't change the I2S mode if any controller is active on this
* channel.
*/
if (any_active(i2s) &&
((mod & (sdf_mask | lrp_rlow | mod_slave)) != tmp)) {
+ spin_unlock(i2s->lock);
dev_err(&i2s->pdev->dev,
"%s:%d Other DAI busy\n", __func__, __LINE__);
return -EAGAIN;
@@ -653,6 +661,7 @@ 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);
return 0;
}
@@ -661,16 +670,16 @@ static int i2s_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
{
struct i2s_dai *i2s = to_info(dai);
- u32 mod = readl(i2s->addr + I2SMOD);
+ u32 mod, mask = 0, val = 0;
if (!is_secondary(i2s))
- mod &= ~(MOD_DC2_EN | MOD_DC1_EN);
+ mask |= (MOD_DC2_EN | MOD_DC1_EN);
switch (params_channels(params)) {
case 6:
- mod |= MOD_DC2_EN;
+ val |= MOD_DC2_EN;
case 4:
- mod |= MOD_DC1_EN;
+ val |= MOD_DC1_EN;
break;
case 2:
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
@@ -692,44 +701,49 @@ static int i2s_hw_params(struct snd_pcm_substream *substream,
}
if (is_secondary(i2s))
- mod &= ~MOD_BLCS_MASK;
+ mask |= MOD_BLCS_MASK;
else
- mod &= ~MOD_BLCP_MASK;
+ mask |= MOD_BLCP_MASK;
if (is_manager(i2s))
- mod &= ~MOD_BLC_MASK;
+ mask |= MOD_BLC_MASK;
switch (params_width(params)) {
case 8:
if (is_secondary(i2s))
- mod |= MOD_BLCS_8BIT;
+ val |= MOD_BLCS_8BIT;
else
- mod |= MOD_BLCP_8BIT;
+ val |= MOD_BLCP_8BIT;
if (is_manager(i2s))
- mod |= MOD_BLC_8BIT;
+ val |= MOD_BLC_8BIT;
break;
case 16:
if (is_secondary(i2s))
- mod |= MOD_BLCS_16BIT;
+ val |= MOD_BLCS_16BIT;
else
- mod |= MOD_BLCP_16BIT;
+ val |= MOD_BLCP_16BIT;
if (is_manager(i2s))
- mod |= MOD_BLC_16BIT;
+ val |= MOD_BLC_16BIT;
break;
case 24:
if (is_secondary(i2s))
- mod |= MOD_BLCS_24BIT;
+ val |= MOD_BLCS_24BIT;
else
- mod |= MOD_BLCP_24BIT;
+ val |= MOD_BLCP_24BIT;
if (is_manager(i2s))
- mod |= MOD_BLC_24BIT;
+ val |= MOD_BLC_24BIT;
break;
default:
dev_err(&i2s->pdev->dev, "Format(%d) not supported\n",
params_format(params));
return -EINVAL;
}
+
+ spin_lock(i2s->lock);
+ mod = readl(i2s->addr + I2SMOD);
+ mod = (mod & ~mask) | val;
writel(mod, i2s->addr + I2SMOD);
+ spin_unlock(i2s->lock);
samsung_asoc_init_dma_data(dai, &i2s->dma_playback, &i2s->dma_capture);
@@ -979,6 +993,7 @@ static int samsung_i2s_dai_probe(struct snd_soc_dai *dai)
{
struct i2s_dai *i2s = to_info(dai);
struct i2s_dai *other = get_other_dai(i2s);
+ unsigned long flags;
if (is_secondary(i2s)) { /* If this is probe on the secondary DAI */
samsung_asoc_init_dma_data(dai, &other->sec_dai->dma_playback,
@@ -999,11 +1014,14 @@ static int samsung_i2s_dai_probe(struct snd_soc_dai *dai)
i2s->rfs = 0;
i2s->bfs = 0;
i2s->rclk_srcrate = 0;
+
+ spin_lock_irqsave(i2s->lock, flags);
i2s_txctrl(i2s, 0);
i2s_rxctrl(i2s, 0);
i2s_fifo(i2s, FIC_TXFLUSH);
i2s_fifo(other, FIC_TXFLUSH);
i2s_fifo(i2s, FIC_RXFLUSH);
+ spin_unlock_irqrestore(i2s->lock, flags);
/* Gate CDCLK by default */
if (!is_opened(other))
@@ -1018,8 +1036,11 @@ static int samsung_i2s_dai_remove(struct snd_soc_dai *dai)
struct i2s_dai *i2s = snd_soc_dai_get_drvdata(dai);
if (!is_secondary(i2s)) {
- if (i2s->quirks & QUIRK_NEED_RSTCLR)
+ if (i2s->quirks & QUIRK_NEED_RSTCLR) {
+ spin_lock(i2s->lock);
writel(0, i2s->addr + I2SCON);
+ spin_unlock(i2s->lock);
+ }
}
return 0;
--
1.7.9.5
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