Re: [PATCH v6 2/2] i2c: qcom-geni: Add dynamic transfer timeout based on transfer length and frequency

[Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com>]

On 7/20/2026 5:11 PM, Aniket Randive wrote:
[...]

> ---
>   drivers/i2c/busses/i2c-qcom-geni.c | 37 +++++++++++++++++++++++++++++--------
>   1 file changed, 29 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> index 96dbf04138be..d6fab3aa8468 100644
> --- a/drivers/i2c/busses/i2c-qcom-geni.c
> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> @@ -74,9 +74,14 @@ enum geni_i2c_err_code {
>   #define PACKING_BYTES_PW	4
>   
>   #define ABORT_TIMEOUT		HZ
> -#define XFER_TIMEOUT		HZ
>   #define RST_TIMEOUT		HZ
>   
> +/* 9 bits per byte (8 data + 1 ACK), 10x safety margin */
> +#define I2C_TIMEOUT_SAFETY_COEFFICIENT	10
> +
> +/* 300ms floor: budget for clock stretching; slave may hold SCL low indefinitely */
> +#define I2C_TIMEOUT_MIN_USEC		300000
> +
Let other expert suggest if pass from DTSI or hardcode here. because 
this let all other controller drivers to make change. I request to 
conclude on discussion, i kept my point in earlier patch.
>   struct geni_i2c_desc {
>   	bool no_dma_support;
>   	unsigned int tx_fifo_depth;
> @@ -471,7 +476,9 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
>   	}
>   
>   	cur = gi2c->cur;
> -	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
> +	i2c_update_timeout(&gi2c->adap, gi2c->clk_freq_out, len,
> +			   I2C_TIMEOUT_SAFETY_COEFFICIENT, I2C_TIMEOUT_MIN_USEC);
> +	time_left = wait_for_completion_timeout(&gi2c->done, gi2c->adap.timeout);
>   	if (!time_left)
>   		geni_i2c_abort_xfer(gi2c);
>   
> @@ -513,7 +520,9 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
>   		writel_relaxed(1, se->base + SE_GENI_TX_WATERMARK_REG);
>   
>   	cur = gi2c->cur;
> -	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
> +	i2c_update_timeout(&gi2c->adap, gi2c->clk_freq_out, len,
> +			   I2C_TIMEOUT_SAFETY_COEFFICIENT, I2C_TIMEOUT_MIN_USEC);
Expect some discussion or conclusion from other experts if need to hard 
code these coefficient or pass from DTSI. if core can read like existing 
i2c_parse_fw_timings(), it would become generic to every i2c adapter driver.
> +	time_left = wait_for_completion_timeout(&gi2c->done, gi2c->adap.timeout);
>   	if (!time_left)
>   		geni_i2c_abort_xfer(gi2c);
>   [...]