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Diffstat (limited to 'sound/arm/aaci.c')
-rw-r--r--sound/arm/aaci.c42
1 files changed, 23 insertions, 19 deletions
diff --git a/sound/arm/aaci.c b/sound/arm/aaci.c
index 21ff6296d16..24d3013c023 100644
--- a/sound/arm/aaci.c
+++ b/sound/arm/aaci.c
@@ -30,6 +30,8 @@
#define DRIVER_NAME "aaci-pl041"
+#define FRAME_PERIOD_US 21
+
/*
* PM support is not complete. Turn it off.
*/
@@ -64,8 +66,8 @@ static void aaci_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
unsigned short val)
{
struct aaci *aaci = ac97->private_data;
+ int timeout;
u32 v;
- int timeout = 5000;
if (ac97->num >= 4)
return;
@@ -81,10 +83,13 @@ static void aaci_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
writel(val << 4, aaci->base + AACI_SL2TX);
writel(reg << 12, aaci->base + AACI_SL1TX);
- /*
- * Wait for the transmission of both slots to complete.
- */
+ /* Initially, wait one frame period */
+ udelay(FRAME_PERIOD_US);
+
+ /* And then wait an additional eight frame periods for it to be sent */
+ timeout = FRAME_PERIOD_US * 8;
do {
+ udelay(1);
v = readl(aaci->base + AACI_SLFR);
} while ((v & (SLFR_1TXB|SLFR_2TXB)) && --timeout);
@@ -101,9 +106,8 @@ static void aaci_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
static unsigned short aaci_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
{
struct aaci *aaci = ac97->private_data;
+ int timeout, retries = 10;
u32 v;
- int timeout = 5000;
- int retries = 10;
if (ac97->num >= 4)
return ~0;
@@ -117,10 +121,13 @@ static unsigned short aaci_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
*/
writel((reg << 12) | (1 << 19), aaci->base + AACI_SL1TX);
- /*
- * Wait for the transmission to complete.
- */
+ /* Initially, wait one frame period */
+ udelay(FRAME_PERIOD_US);
+
+ /* And then wait an additional eight frame periods for it to be sent */
+ timeout = FRAME_PERIOD_US * 8;
do {
+ udelay(1);
v = readl(aaci->base + AACI_SLFR);
} while ((v & SLFR_1TXB) && --timeout);
@@ -130,17 +137,13 @@ static unsigned short aaci_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
goto out;
}
- /*
- * Give the AC'97 codec more than enough time
- * to respond. (42us = ~2 frames at 48kHz.)
- */
- udelay(42);
+ /* Now wait for the response frame */
+ udelay(FRAME_PERIOD_US);
- /*
- * Wait for slot 2 to indicate data.
- */
- timeout = 5000;
+ /* And then wait an additional eight frame periods for data */
+ timeout = FRAME_PERIOD_US * 8;
do {
+ udelay(1);
cond_resched();
v = readl(aaci->base + AACI_SLFR) & (SLFR_1RXV|SLFR_2RXV);
} while ((v != (SLFR_1RXV|SLFR_2RXV)) && --timeout);
@@ -179,6 +182,7 @@ aaci_chan_wait_ready(struct aaci_runtime *aacirun, unsigned long mask)
int timeout = 5000;
do {
+ udelay(1);
val = readl(aacirun->base + AACI_SR);
} while (val & mask && timeout--);
}
@@ -874,7 +878,7 @@ static int __devinit aaci_probe_ac97(struct aaci *aaci)
* Give the AC'97 codec more than enough time
* to wake up. (42us = ~2 frames at 48kHz.)
*/
- udelay(42);
+ udelay(FRAME_PERIOD_US * 2);
ret = snd_ac97_bus(aaci->card, 0, &aaci_bus_ops, aaci, &ac97_bus);
if (ret)