Re: PCI device function not being enumerated [Was: PCMCIA not working on Panasonic Toughbook CF-29]

[bluerocksaddles]

Bjorn,

If you folks need a test unit or five, let me know. I can donate any 
Mark CF-29 to the project. (MK 2 or 3 will duplicate the "problem".) 
They are non-pae 386.

Jeff

On 2020-02-25 07:03, Ulf Hansson wrote:
> On Sat, 22 Feb 2020 at 17:56, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> > On Tue, Oct 29, 2019 at 12:02:50PM -0500, Bjorn Helgaas wrote:
> > > [+cc Ulf, Philip, Pierre, Maxim, linux-mmc; see [1] for beginning of
> > > thread, [2] for problem report and the patch Michael tested]
> > >
> > > On Tue, Oct 29, 2019 at 07:58:27PM +1100, Michael . wrote:
> > > > Bjorn and Dominik.
> > > > I am happy to let you know the patch did the trick, it compiled well
> > > > on 5.4-rc4 and my friends in the CC list have tested the modified
> > > > kernel and confirmed that both slots are now working as they should.
> > > > As a group of dedicated Toughbook users and Linux users please accept
> > > > our thanks your efforts and assistance is greatly appreciated.
> > > >
> > > > Now that we know this patch works what kernel do you think it will be
> > > > released in? Will it make 5.4 or will it be put into 5.5 development
> > > > for further testing?
> > >
> > > That patch was not intended to be a fix; it was just to test my guess
> > > that the quirk might be related.
> > >
> > > Removing the quirk solved the problem *you're* seeing, but the quirk
> > > was added in the first place to solve some other problem, and if we
> > > simply remove the quirk, we may reintroduce the original problem.
> > >
> > > So we have to look at the history and figure out some way to solve
> > > both problems.  I cc'd some people who might have insight.  Here are
> > > some commits that look relevant:
> > >
> > >   5ae70296c85f ("mmc: Disabler for Ricoh MMC controller")
> > >   03cd8f7ebe0c ("ricoh_mmc: port from driver to pci quirk")
> > >
> > >
> > > [1] https://lore.kernel.org/r/CAFjuqNi+knSb9WVQOahCVFyxsiqoGgwoM7Z1aqDBebNzp_-jYw@xxxxxxxxxxxxxx/
> > > [2] https://lore.kernel.org/r/20191021160952.GA229204@xxxxxxxxxx/
> >
> > I guess this problem is still unfixed?  I hate the fact that we broke
> > something that used to work.
> >
> > Maybe we need some sort of DMI check in ricoh_mmc_fixup_rl5c476() so
> > we skip it for Toughbooks?  Or maybe we limit the quirk to the
> > machines where it was originally needed?
>
> Both options seems reasonable to me. Do you have time to put together a 
> patch?
>
> Kind regards
> Uffe