Re: bcm2835

the comment indicates that timeout value is too low. surely, there
must be some place where the timing constraint is indicated because of
which this quirk was put in. or is it that the datasheet doesn't
require this -but in practice, the timeout needs to be increased? if
someone else has added it -maybe they can tell me.

thanks
-kamal

On Wed, May 19, 2021 at 6:50 PM Kyle Evans <kevans@freebsd.org> wrote:
>
> On Wed, May 19, 2021 at 8:12 AM Kamal R. Prasad <kamalpr@gmail.com> wrote:
> > On Wed, May 19, 2021 at 6:08 PM Kyle Evans <kevans@freebsd.org> wrote:
> > >
> > > On Wed, May 19, 2021 at 12:27 AM Kamal R. Prasad <kamalpr@gmail.com> wrote:
> > > >
> > > > hello,
> > > >
> > > > in file
> > > > sys/arm/broadcom/bcm2835/bcm2835_sdhci.c
> > > >
> > > > there is a constant
> > > > SDHCI_QUIRK_BROKEN_TIMEOUT_VAL
> > > > can someone tell me why this was introduced and does it correspond to
> > > > anything in the datasheet?
> > > >
> > >
> > > Hi,
> > >
> > > This was added by gonzo@ back in r242321. It doesn't really correspond
> > > to anything in the datasheet, but before I committed r354560 that
> > > moved it around I did try to remove it and observed that it was still
> > > a problem with either the RPi3 or RPi4.
> > >
> > > Thanks,
> > >
> > > Kyle Evans
> >
> > Hi!
> >
> > can you tell me more on why removing it was a problem for rpi3 or
> > rpi4? i am trying to understand the significance of this #define.
> >
> > thanks
> > -kamal
> >
>
> You'll find better insight from the comment at its definition and
> implementation:
> http://bxr.su/FreeBSD/sys/dev/sdhci/sdhci.h#60
> http://bxr.su/FreeBSD/sys/dev/sdhci/sdhci.c#1814
>
> My very vague recollection is that the advertised timeout is too low,
> but it's probably an implementation issue.
>
> Thanks,
>
> Kyle Evans