Re: [PATCH 2/7] spi: fsi: Fix clock running too fast

Joel Stanley
2020-08-25T07:10:48Z

On Thu, 20 Aug 2020 at 21:06, Eddie James <eajames@linux.ibm.com> wrote:
>
>
> On 8/20/20 12:12 PM, Mark Brown wrote:
> > On Thu, Aug 20, 2020 at 12:02:23PM -0500, Eddie James wrote:
> >> From: Brad Bishop <bradleyb@fuzziesquirrel.com>
> >>
> >> Use a clock divider tuned to a 200MHz FSI clock. Use of the previous
> >> divider at 200MHz results in corrupt data from endpoint devices. Ideally
> >> the clock divider would be calculated from the FSI clock, but that
> >> would require some significant work on the FSI driver.
> > Presumably this divider was chosen for FSI clocks that aren't 200MHz -
> > how will those be handled?
>
>
> They aren't handled at the moment, but 200MHz FSI represents the worst
> case, as it's the maximum. Slower FSI clocks will simply result in
> slower SPI clocks.

That would be a good addition to the commit message, as I had the same
question too.

Cheers,

Joel