On 2/3/2018 1:28 PM, Abhishek Sahu wrote:
> Currently the completion timeout is being taken according to
> maximum transfer length which is too high if SCL is operating in
> high frequency. This patch calculates timeout on the basis of
> one-byte transfer time and uses the same for completion timeout.
> 
> Signed-off-by: Abhishek Sahu <abs...@codeaurora.org>
> ---
>  drivers/i2c/busses/i2c-qup.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
> index a91fc70..6df65ea 100644
> --- a/drivers/i2c/busses/i2c-qup.c
> +++ b/drivers/i2c/busses/i2c-qup.c
> @@ -130,8 +130,8 @@
>  #define MX_TX_RX_LEN                 SZ_64K
>  #define MX_BLOCKS                    (MX_TX_RX_LEN / QUP_READ_LIMIT)
>  
> -/* Max timeout in ms for 32k bytes */
> -#define TOUT_MAX                     300
> +/* Min timeout for i2c transfers */
> +#define TOUT_MIN                     2
>  

 may be you can mention, why is this 2 ?

Regards,
 Sricharan


>  /* Default values. Use these if FW query fails */
>  #define DEFAULT_CLK_FREQ 100000
> @@ -172,6 +172,7 @@ struct qup_i2c_dev {
>       int                     in_blk_sz;
>  
>       unsigned long           one_byte_t;
> +     unsigned long           xfer_timeout;
>       struct qup_i2c_block    blk;
>  
>       struct i2c_msg          *msg;
> @@ -845,7 +846,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, 
> struct i2c_msg *msg,
>               dma_async_issue_pending(qup->brx.dma);
>       }
>  
> -     if (!wait_for_completion_timeout(&qup->xfer, TOUT_MAX * HZ)) {
> +     if (!wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout)) {
>               dev_err(qup->dev, "normal trans timed out\n");
>               ret = -ETIMEDOUT;
>       }
> @@ -1601,6 +1602,8 @@ static int qup_i2c_probe(struct platform_device *pdev)
>        */
>       one_bit_t = (USEC_PER_SEC / clk_freq) + 1;
>       qup->one_byte_t = one_bit_t * 9;
> +     qup->xfer_timeout = TOUT_MIN * HZ +
> +                         usecs_to_jiffies(MX_TX_RX_LEN * qup->one_byte_t);
>  
>       dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n",
>               qup->in_blk_sz, qup->in_fifo_sz,
> 

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