ALSA: hda - Delay switching to polling mode if an interrupt was missing
Maxim Levitsky [Thu, 4 Feb 2010 20:21:47 +0000 (22:21 +0200)]
My sound codec seems sometimes (very rarely) to omit interrupts (ALC268)
However, interrupt mode still works.
Thus if we get timeout, poll the codec once.

If we get 3 such polls in a row, then switch to polling mode.

This patch is maybe an bandaid, but this might be a workaround for hardware bug.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_intel.c

index 565de38..d853e2c 100644 (file)
@@ -426,6 +426,7 @@ struct azx {
 
        /* flags */
        int position_fix;
+       int poll_count;
        unsigned int running :1;
        unsigned int initialized :1;
        unsigned int single_cmd :1;
@@ -506,7 +507,7 @@ static char *driver_short_names[] __devinitdata = {
 #define get_azx_dev(substream) (substream->runtime->private_data)
 
 static int azx_acquire_irq(struct azx *chip, int do_disconnect);
-
+static int azx_send_cmd(struct hda_bus *bus, unsigned int val);
 /*
  * Interface for HD codec
  */
@@ -664,11 +665,12 @@ static unsigned int azx_rirb_get_response(struct hda_bus *bus,
 {
        struct azx *chip = bus->private_data;
        unsigned long timeout;
+       int do_poll = 0;
 
  again:
        timeout = jiffies + msecs_to_jiffies(1000);
        for (;;) {
-               if (chip->polling_mode) {
+               if (chip->polling_mode || do_poll) {
                        spin_lock_irq(&chip->reg_lock);
                        azx_update_rirb(chip);
                        spin_unlock_irq(&chip->reg_lock);
@@ -676,6 +678,9 @@ static unsigned int azx_rirb_get_response(struct hda_bus *bus,
                if (!chip->rirb.cmds[addr]) {
                        smp_rmb();
                        bus->rirb_error = 0;
+
+                       if (!do_poll)
+                               chip->poll_count = 0;
                        return chip->rirb.res[addr]; /* the last value */
                }
                if (time_after(jiffies, timeout))
@@ -688,6 +693,16 @@ static unsigned int azx_rirb_get_response(struct hda_bus *bus,
                }
        }
 
+       if (!chip->polling_mode && chip->poll_count < 2) {
+               snd_printdd(SFX "azx_get_response timeout, "
+                          "polling the codec once: last cmd=0x%08x\n",
+                          chip->last_cmd[addr]);
+               do_poll = 1;
+               chip->poll_count++;
+               goto again;
+       }
+
+
        if (!chip->polling_mode) {
                snd_printk(KERN_WARNING SFX "azx_get_response timeout, "
                           "switching to polling mode: last cmd=0x%08x\n",