Re: [PATCH 3.12 137/142] mmc: sh_mmcif: Fix timeout value for command request

Simon Horman
2015-05-18T00:37:40Z

On Sat, May 16, 2015 at 01:23:20PM +0200, Jiri Slaby wrote:
> On 05/16/2015, 01:05 PM, Albino Biasutti Neto wrote:
> > 2015-05-16 4:38 GMT-03:00 Jiri Slaby <jslaby@suse.cz>:
> >> commit bad4371d87d1d1ed1aecd9c9cc21c41ac3f289c8 upstream.
> >>
> >> f9fd54f22e ("mmc: sh_mmcif: Use msecs_to_jiffies() for host->timeout")
> >> changed the timeout value from 1000 jiffies to 1s. In the case where
> >> HZ is 1000 the values are the same. However, for smaller HZ values the
> >> timeout is now smaller, 1s instead of 10s in the case of HZ=100.
> >>
> >> Since the timeout occurs in spite of a normal data transfer a timeout of
> >> 10s seems more appropriate. This restores the previous timeout in the
> >> case where HZ=100 and results in an increase over the previous timeout
> >> for larger values of HZ.
> >>
> >> Fixes: f9fd54f22e ("mmc: sh_mmcif: Use msecs_to_jiffies() for host->timeout")
> >
> > What is best 1s or 10s ? is 1s. The less time is faster, but HZ=100
> > not 1000. 10s the longer answer.
> >
> > True ?
>
> Sorry, what?

My understanding is that there is a desire to have a timeout of 10s
as 1s has turned out to be too short in practice.

Prior to f9fd54f22e the timeout was 10s for HZ=100, and it is my
understanding that on SH mobile HZ=100 is the normal case.