ALSA: hda - Check CORB overflow
Add an overflow check of CORB in HD-audio controller and codec drivers
so that flood of sequential writes would work properly.
In the controller side, add a check of CORB read-pointer to make
returning -EAGAIN when it's full. Meanwhile in the codec side, when
-EAGAIN error is received, it retries the write after flushing the
pending verbs (calling get_response() essentially does it).
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 0b6aeba..0430436 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -797,7 +797,7 @@
{
struct azx *chip = bus->private_data;
unsigned int addr = azx_command_addr(val);
- unsigned int wp;
+ unsigned int wp, rp;
spin_lock_irq(&chip->reg_lock);
@@ -806,11 +806,18 @@
if (wp == 0xffff) {
/* something wrong, controller likely turned to D3 */
spin_unlock_irq(&chip->reg_lock);
- return -1;
+ return -EIO;
}
wp++;
wp %= ICH6_MAX_CORB_ENTRIES;
+ rp = azx_readw(chip, CORBRP);
+ if (wp == rp) {
+ /* oops, it's full */
+ spin_unlock_irq(&chip->reg_lock);
+ return -EAGAIN;
+ }
+
chip->rirb.cmds[addr]++;
chip->corb.buf[wp] = cpu_to_le32(val);
azx_writel(chip, CORBWP, wp);