Hi,
On Wed, May 24, 2023 at 10:40:02AM +0800, carlos.song@xxxxxxx wrote:
> From: Gao Pan <pandy.gao@xxxxxxx>
>
> A NACK flag in ISR means i2c bus error. In such codition,
> there is no need to do read/write operation. It's better
> to return ISR directly and then stop i2c transfer.
>
> Fixes: a55fa9d0e42e ("i2c: imx-lpi2c: add low power i2c bus driver")
> Signed-off-by: Gao Pan <pandy.gao@xxxxxxx>
> Signed-off-by: Carlos Song <carlos.song@xxxxxxx>
looks good to me, just a little note.
> ---
> drivers/i2c/busses/i2c-imx-lpi2c.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
> index 1af0a637d7f1..11240bf8e8e2 100644
> --- a/drivers/i2c/busses/i2c-imx-lpi2c.c
> +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
> @@ -514,15 +514,17 @@ static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id)
> temp = readl(lpi2c_imx->base + LPI2C_MSR);
> temp &= enabled;
>
> + if (temp & MSR_NDF) {
> + complete(&lpi2c_imx->complete);
> + goto ret;
> + }
> +
> if (temp & MSR_RDF)
else if () and remove goto and brackets. You have used the
"else if" below and we can keep it consistent.
This way the commit log should be a bit different as we
decide to check exclusively using else if's for the active bits.
This way we also stop processing the MSR register if a NACK is
received.
With the above I can give you a conditional r-b: are you able to
pull Dong into this review as Wolfram asked?
Thank you,
Andi
> lpi2c_imx_read_rxfifo(lpi2c_imx);
> -
> - if (temp & MSR_TDF)
> + else if (temp & MSR_TDF)
> lpi2c_imx_write_txfifo(lpi2c_imx);
>
> - if (temp & MSR_NDF)
> - complete(&lpi2c_imx->complete);
> -
> +ret:
> return IRQ_HANDLED;
> }
>
> --
> 2.34.1
>
