Hi Marek,
On Wed, Oct 25, 2023 at 02:17:23PM +0200, Marek Szyprowski wrote:
> To properly handle read transfers in polling mode, no waiting for the ACK
> state is needed as it will never come. Just wait a bit to ensure start
> state is on the bus and continue processing next bytes.
>
> Fixes: 117053f77a5a ("i2c: s3c2410: Add polling mode support")
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-s3c2410.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
> index 127eb3805fac..f9dcb1112a61 100644
> --- a/drivers/i2c/busses/i2c-s3c2410.c
> +++ b/drivers/i2c/busses/i2c-s3c2410.c
> @@ -216,8 +216,13 @@ static bool is_ack(struct s3c24xx_i2c *i2c)
> int tries;
>
> for (tries = 50; tries; --tries) {
> - if (readl(i2c->regs + S3C2410_IICCON)
> - & S3C2410_IICCON_IRQPEND) {
> + unsigned long tmp = readl(i2c->regs + S3C2410_IICCON);
> +
> + if (!(tmp & S3C2410_IICCON_ACKEN)) {
> + usleep_range(100, 200);
> + return true;
What is the real issue here? Is the value of S3C2410_IICCON_ACKEN
enabling/disabling irq's?
Besides, if we use polling mode, shouldn't we disable the acks
already in probe (even though they are disabled by default),
never enable them before starting the message and avoid checking
here everytime?
Andi
> + }
> + if (tmp & S3C2410_IICCON_IRQPEND) {
> if (!(readl(i2c->regs + S3C2410_IICSTAT)
> & S3C2410_IICSTAT_LASTBIT))
> return true;
> --
> 2.34.1
>
