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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: 117053f77a ("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>
This commit is contained in:
Marek Szyprowski 2023-11-08 17:43:53 +01:00 committed by Greg Kroah-Hartman
parent 63892860b0
commit 2c46871ac4
1 changed files with 10 additions and 17 deletions
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25
drivers/i2c/busses/i2c-s3c2410.c
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@ -283,16 +283,6 @@ 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)
@ -699,7 +689,7 @@ 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);
@ -719,15 +709,18 @@ 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);
}
ret = i2c->msg_idx;