Re: [PATCH 08/12] i2c: qup: change completion timeout according to transfer length

[Abhishek Sahu]

On 2018-02-16 10:18, Sricharan R wrote:
> 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 <absahu@xxxxxxxxxxxxxx>
> > ---
> >  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 ?

 This 2 seconds is timeout which I am adding on the top of maximum
 xfer time calculated from bus speed to compensate the interrupt
 latency and other factors. It will make xfer timeout minimum as
 2 seconds.

 I will update the comment to explain it in more detail.

 Thanks,
 Abhishek