1 files changed, 18 insertions, 3 deletions

diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index d27072b2249f..72902e0bbfa7 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -35,9 +35,9 @@
 #include <linux/clk.h>
 #include <linux/cpufreq.h>
 #include <linux/slab.h>
+#include <linux/io.h>
 
 #include <asm/irq.h>
-#include <asm/io.h>
 
 #include <plat/regs-iic.h>
 #include <plat/iic.h>
@@ -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;