[ALSA] oxygen: use AC97 interrupt

After an AC97 register read or write, use the AC97 interrupt instead of
polling to wait for the access to be completed.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

1 files changed, 16 insertions, 8 deletions

diff --git a/sound/pci/oxygen/oxygen_io.c b/sound/pci/oxygen/oxygen_io.c
index d0cdce041dd8..74e23ef9c946 100644
--- a/sound/pci/oxygen/oxygen_io.c
+++ b/sound/pci/oxygen/oxygen_io.c
@@ -85,14 +85,22 @@ EXPORT_SYMBOL(oxygen_write32_masked);
 
 static int oxygen_ac97_wait(struct oxygen *chip, unsigned int mask)
 {
-        unsigned long timeout = jiffies + msecs_to_jiffies(1);
-        do {
-                udelay(5);
-                cond_resched();
-                if (oxygen_read8(chip, OXYGEN_AC97_INTERRUPT_STATUS) & mask)
-                        return 0;
-        } while (time_after_eq(timeout, jiffies));
-        return -EIO;
+        u8 status = 0;
+
+        /*
+         * Reading the status register also clears the bits, so we have to save
+         * the read bits in status.
+         */
+        wait_event_timeout(chip->ac97_waitqueue,
+                           ({ status |= oxygen_read8(chip, OXYGEN_AC97_INTERRUPT_STATUS);
+                              status & mask; }),
+                           msecs_to_jiffies(1) + 1);
+        /*
+         * Check even after a timeout because this function should not require
+         * the AC'97 interrupt to be enabled.
+         */
+        status |= oxygen_read8(chip, OXYGEN_AC97_INTERRUPT_STATUS);
+        return status & mask ? 0 : -EIO;
 }
 
 /*