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path: root/drivers/i2c/busses/i2c-s3c2410.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-s3c2410.c')
-rw-r--r--drivers/i2c/busses/i2c-s3c2410.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index d27072b..ec3256c 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -482,7 +482,8 @@ static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c)
static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
struct i2c_msg *msgs, int num)
{
- unsigned long timeout;
+ unsigned long iicstat, timeout;
+ int spins = 20;
int ret;
if (i2c->suspended)
@@ -521,7 +522,21 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
/* ensure the stop has been through the bus */
- msleep(1);
+ dev_dbg(i2c->dev, "waiting for bus idle\n");
+
+ /* first, try busy waiting briefly */
+ do {
+ iicstat = readl(i2c->regs + S3C2410_IICSTAT);
+ } while ((iicstat & S3C2410_IICSTAT_START) && --spins);
+
+ /* if that timed out sleep */
+ if (!spins) {
+ msleep(1);
+ iicstat = readl(i2c->regs + S3C2410_IICSTAT);
+ }
+
+ if (iicstat & S3C2410_IICSTAT_START)
+ dev_warn(i2c->dev, "timeout waiting for bus idle\n");
out:
return ret;