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authorMarek Szyprowski <m.szyprowski@samsung.com>2023-11-08 17:43:53 +0100
committerWolfram Sang <wsa@kernel.org>2024-01-18 21:10:42 +0100
commit990489e1042c6c5d6bccf56deca68f8dbeed8180 (patch)
tree6a7b00fa7c5c332449bc864af5ff172cef6ebdac /drivers/i2c
parenti2c: s3c24xx: fix read transfers in polling mode (diff)
downloadlinux-990489e1042c6c5d6bccf56deca68f8dbeed8180.tar.xz
linux-990489e1042c6c5d6bccf56deca68f8dbeed8180.zip
i2c: s3c24xx: fix transferring more than one message in polling mode
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>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-s3c2410.c27
1 files changed, 10 insertions, 17 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index bf9a5670ef33..c0fe96a4f2c4 100644
--- 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)
@@ -694,7 +684,7 @@ 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);
@@ -714,16 +704,19 @@ 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;
/*