Hi Wolfram,
On Wed, May 20, 2020 at 5:49 PM Wolfram Sang
<wsa+renesas@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, May 20, 2020 at 04:30:33PM +0200, Geert Uytterhoeven wrote:
> > On Tue, May 19, 2020 at 5:24 PM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> > > Before calling tmio_mmc_host_probe(), the caller is required to enable
> > > clocks for its device, as to make it accessible when reading/writing
> > > registers during probe.
> > >
> > > Therefore, the responsibility to disable these clocks, in the error path of
> > > ->probe() and during ->remove(), is better managed outside
> > > tmio_mmc_host_remove(). As a matter of fact, callers of
> > > tmio_mmc_host_remove() already expects this to be the behaviour.
> > >
> > > However, there's a problem with tmio_mmc_host_remove() when the Kconfig
> > > option, CONFIG_PM, is set. More precisely, tmio_mmc_host_remove() may then
> > > disable the clock via runtime PM, which leads to clock enable/disable
> > > imbalance problems, when the caller of tmio_mmc_host_remove() also tries to
> > > disable the same clocks.
> > >
> > > To solve the problem, let's make sure tmio_mmc_host_remove() leaves the
> > > device with clocks enabled, but also make sure to disable the IRQs, as we
> > > normally do at ->runtime_suspend().
> > >
> > > Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > > Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> > > Tested-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> > > Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> >
> > Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> >
> > (on R-Car Gen2, various Gen3, SH-Mobile AG5, R-Mobile A1, R-Mobile APE6,
> > RZ/A1, and RZ/A2)
>
> Thanks, Geert! If it is not too much to ask, could you try re-applying
> commit 7a7dab237027 ("mmc: tmio: remove workaround for NON_REMOVABLE")
> on top of all these patches and see if your NFS is still stalled?
>
> Sidenote: we still need to tackle the problem when SCC hangs because it
> has no clock. However, I am still interested if all the PM updates have
> an impact in the beaviour you observed here[1].
>
> [1] https://patchwork.kernel.org/patch/11149285/
I reverted "[PATCH] WIP: clk: renesas: rcar-gen3: enable SDnH clk for HS
modes" (which I still had applied in my local tree), and reapplied "mmc:
tmio: remove workaround for NON_REMOVABLE", but I cannot reproduce the
issue, with or without the top 3 commits on mmc/next:
ff5a1a63febb0761 mmc: tmio: Further fixup runtime PM management at remove
774c44ceff3c5b3f mmc: tmio: Make sure the PM domain is 'started' while probing
4863bb62a87786ec mmc: renesas_sdhi: remove manual clk handling
Let's see if I can bisect where it was fixed...
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
