i2c: s3c24xx: fix transferring more than one message in polling mode

[ Upstream commit 990489e1042c6c5d6bccf56deca68f8dbeed8180 ]

To properly handle ACK on the bus when transferring more than one
message in polling mode, move the polling handling loop from
s3c24xx_i2c_message_start() to s3c24xx_i2c_doxfer(). This way
i2c_s3c_irq_nextbyte() is always executed till the end, properly
acknowledging the IRQ bits and no recursive calls to
i2c_s3c_irq_nextbyte() are made.

While touching this, also fix finishing transfers in polling mode by
using common code path and always waiting for the bus to become idle
and disabled.

Fixes: 117053f77a5a ("i2c: s3c2410: Add polling mode support")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index fdd7a42..c324cb3 100644 (file)
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -279,16 +279,6 @@ static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c,
 
        stat |= S3C2410_IICSTAT_START;
        writel(stat, i2c->regs + S3C2410_IICSTAT);
-
-       if (i2c->quirks & QUIRK_POLL) {
-               while ((i2c->msg_num != 0) && is_ack(i2c)) {
-                       i2c_s3c_irq_nextbyte(i2c, stat);
-                       stat = readl(i2c->regs + S3C2410_IICSTAT);
-
-                       if (stat & S3C2410_IICSTAT_ARBITR)
-                               dev_err(i2c->dev, "deal with arbitration loss\n");
-               }
-       }
 }
 
 static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret)
@@ -695,7 +685,7 @@ static void s3c24xx_i2c_wait_idle(struct s3c24xx_i2c *i2c)
 static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
                              struct i2c_msg *msgs, int num)
 {
-       unsigned long timeout;
+       unsigned long timeout = 0;
        int ret;
 
        ret = s3c24xx_i2c_set_master(i2c);
@@ -715,16 +705,19 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
        s3c24xx_i2c_message_start(i2c, msgs);
 
        if (i2c->quirks & QUIRK_POLL) {
-               ret = i2c->msg_idx;
+               while ((i2c->msg_num != 0) && is_ack(i2c)) {
+                       unsigned long stat = readl(i2c->regs + S3C2410_IICSTAT);
 
-               if (ret != num)
-                       dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
+                       i2c_s3c_irq_nextbyte(i2c, stat);
 
-               goto out;
+                       stat = readl(i2c->regs + S3C2410_IICSTAT);
+                       if (stat & S3C2410_IICSTAT_ARBITR)
+                               dev_err(i2c->dev, "deal with arbitration loss\n");
+               }
+       } else {
+               timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
        }
 
-       timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
-
        ret = i2c->msg_idx;
 
        /*