To properly handle ACK on the bus when transferring more than one
message in polled 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.
Also fix finishing transfers in polled 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@xxxxxxxxxxx>
---
drivers/i2c/busses/i2c-s3c2410.c | 25 ++++++++++---------------
1 file changed, 10 insertions(+), 15 deletions(-)
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index f9dcb1112a61..8da85cb42980 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -275,16 +275,6 @@ 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)
@@ -691,7 +681,7 @@ 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);
@@ -711,16 +701,21 @@ 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");
+ }
+ goto skip_waiting;
}
timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
+ skip_waiting:
ret = i2c->msg_idx;
/*
--
2.34.1
