ALSA: AACI: fix multiple IRQ claiming

[linux-3.10.git] / sound / arm / aaci.c

diff --git a/sound/arm/aaci.c b/sound/arm/aaci.c
index 91acc9a243ec47dec8aabb6a67bcdd9b4f4aa671..65685afd8f77c65d16cd2551626c04b8066b08fe 100644 (file)
--- 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;
@@ -81,14 +83,17 @@ 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);
 
-       if (!timeout)
+       if (v & (SLFR_1TXB|SLFR_2TXB))
                dev_err(&aaci->dev->dev,
                        "timeout waiting for write to complete\n");
 
@@ -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;
@@ -117,35 +121,34 @@ 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);
 
-       if (!timeout) {
+       if (v & SLFR_1TXB) {
                dev_err(&aaci->dev->dev, "timeout on slot 1 TX busy\n");
                v = ~0;
                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);
 
-       if (!timeout) {
+       if (v != (SLFR_1RXV|SLFR_2RXV)) {
                dev_err(&aaci->dev->dev, "timeout on RX valid\n");
                v = ~0;
                goto out;
@@ -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--);
 }
@@ -366,7 +370,7 @@ static int __aaci_pcm_open(struct aaci *aaci,
                           struct aaci_runtime *aacirun)
 {
        struct snd_pcm_runtime *runtime = substream->runtime;
-       int ret;
+       int ret = 0;
 
        aacirun->substream = substream;
        runtime->private_data = aacirun;
@@ -387,14 +391,15 @@ static int __aaci_pcm_open(struct aaci *aaci,
         */
        runtime->hw.fifo_size = aaci->fifosize * 2;
 
-       ret = request_irq(aaci->dev->irq[0], aaci_irq, IRQF_SHARED|IRQF_DISABLED,
-                         DRIVER_NAME, aaci);
-       if (ret)
-               goto out;
-
-       return 0;
+       mutex_lock(&aaci->irq_lock);
+       if (!aaci->users++) {
+               ret = request_irq(aaci->dev->irq[0], aaci_irq,
+                          IRQF_SHARED | IRQF_DISABLED, DRIVER_NAME, aaci);
+               if (ret != 0)
+                       aaci->users--;
+       }
+       mutex_unlock(&aaci->irq_lock);
 
- out:
        return ret;
 }
 
@@ -410,7 +415,11 @@ static int aaci_pcm_close(struct snd_pcm_substream *substream)
        WARN_ON(aacirun->cr & CR_EN);
 
        aacirun->substream = NULL;
-       free_irq(aaci->dev->irq[0], aaci);
+
+       mutex_lock(&aaci->irq_lock);
+       if (!--aaci->users)
+               free_irq(aaci->dev->irq[0], aaci);
+       mutex_unlock(&aaci->irq_lock);
 
        return 0;
 }
@@ -874,7 +883,7 @@ 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)
@@ -939,6 +948,7 @@ static struct aaci * __devinit aaci_init_card(struct amba_device *dev)
 
        aaci = card->private_data;
        mutex_init(&aaci->ac97_sem);
+       mutex_init(&aaci->irq_lock);
        aaci->card = card;
        aaci->dev = dev;