ASoC: S3C lrsync function made to work with IRQs disabled.

s3c2412_snd_lrsync() maybe reached with IRQs disabled and if LRCLK
is dead due to improper initialization of CPU or CODEC, the system
gets stuck in the loop because jiffies may never get updated.
Implemented counter based wait mechanism for atleast the same
timeout period.

Signed-off-by: Jassi <jassi.brar@samsung.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/sound/soc/s3c24xx/s3c-i2s-v2.c b/sound/soc/s3c24xx/s3c-i2s-v2.c
index aa7af0b8d421e121996332cc71bcafb1b11eaf35..9bc4aa35caab477f918f6f574fadb8ffbf75f319 100644 (file)
--- a/sound/soc/s3c24xx/s3c-i2s-v2.c
+++ b/sound/soc/s3c24xx/s3c-i2s-v2.c
@@ -230,6 +230,8 @@ static void s3c2412_snd_rxctrl(struct s3c_i2sv2_info *i2s, int on)
        pr_debug("%s: IIS: CON=%x MOD=%x FIC=%x\n", __func__, con, mod, fic);
 }
 
+#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
+
 /*
  * Wait for the LR signal to allow synchronisation to the L/R clock
  * from the codec. May only be needed for slave mode.
@@ -237,19 +239,21 @@ static void s3c2412_snd_rxctrl(struct s3c_i2sv2_info *i2s, int on)
 static int s3c2412_snd_lrsync(struct s3c_i2sv2_info *i2s)
 {
        u32 iiscon;
-       unsigned long timeout = jiffies + msecs_to_jiffies(5);
+       unsigned long loops = msecs_to_loops(5);
 
        pr_debug("Entered %s\n", __func__);
 
-       while (1) {
+       while (--loops) {
                iiscon = readl(i2s->regs + S3C2412_IISCON);
                if (iiscon & S3C2412_IISCON_LRINDEX)
                        break;
 
-               if (timeout < jiffies) {
-                       printk(KERN_ERR "%s: timeout\n", __func__);
-                       return -ETIMEDOUT;
-               }
+               cpu_relax();
+       }
+
+       if (!loops) {
+               printk(KERN_ERR "%s: timeout\n", __func__);
+               return -ETIMEDOUT;
        }
 
        return 0;