[ALSA] soc - Fix s3c24xx-i2s LR sync while timer ticks are disabled

When timer ticks are disabled when calling
sound/soc/s3c24xx/s3c24xx-i2s.c:s3c24xx_snd_lrsync
and the LR signal never happens, we loop forever.
This has been observed in the following call chain:
snd_pcm_common_ioctl1 -> snd_pcm_action_lock_irq ->
snd_pcm_action_single
 -> snd_pcm_do_resume -> soc_pcm_trigger -> s3c24xx_i2s_trigger

The patch below changes the timeout mechanism to use udelay, which
doesn't need timer ticks.

Signed-off-by: Werner Almesberger <werner@openmoko.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/sound/soc/s3c24xx/s3c24xx-i2s.c b/sound/soc/s3c24xx/s3c24xx-i2s.c
index ddf8724..4c52f79 100644 (file)
--- a/sound/soc/s3c24xx/s3c24xx-i2s.c
+++ b/sound/soc/s3c24xx/s3c24xx-i2s.c
@@ -175,7 +175,7 @@ static void s3c24xx_snd_rxctrl(int on)
 static int s3c24xx_snd_lrsync(void)
 {
        u32 iiscon;
-       unsigned long timeout = jiffies + msecs_to_jiffies(5);
+       int timeout = 50; /* 5ms */
 
        DBG("Entered %s\n", __func__);
 
@@ -184,8 +184,9 @@ static int s3c24xx_snd_lrsync(void)
                if (iiscon & S3C2410_IISCON_LRINDEX)
                        break;
 
-               if (time_after(jiffies, timeout))
+               if (!timeout--)
                        return -ETIMEDOUT;
+               udelay(100);
        }
 
        return 0;