Re: [PATCH v2] mmc: tmio: move runtime PM enablement to the driver implementations

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Niklas,

On Mon, Apr 15, 2019 at 1:10 PM Wolfram Sang <wsa@the-dreams.de> wrote:
> On Thu, Apr 11, 2019 at 12:22:40AM +0200, Niklas Söderlund wrote:
> > Both the Renesas and Uniphier implementations perform actions which
> > affect runtime PM before calling into the core tmio_mmc_host_probe()

Do you know which pm_runtime_*() calls were done too early?
I guess they returned an error, which is not checked?

I checked the various pm_runtime_get*() calls, but none of them failed,
while they typically return -EACCES when called too early.

> > which enabled runtime PM. Move pm_runtime_enable() from the core and
> > tmio_mmc_host_probe() into each drivers probe() so it can be called
> > before any clocks or other resources are switched on.
> >
> > Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > ---
>
> Thanks for keeping at this. Setting up the APE6 board for further tests
> was painful, I understood that.
>
> Since you lost the cover-letter from the last series, I think it should
> be mentioned that this fixes a clock imbalance problem (at least on
> Gen3).
>
> For the APE6 tests, we need to wait until Geert comes back. I surely
> would like his input. And Yamada-san's, too, to make sure his platform
> also benefits.

Thanks, but I still see a clock imbalances in /sys/kernel/debug/clk/clk_summary
when comparing before/after s2ram.

On ape6evm:

-   mmcif0   2   2   0   100000000   0     0  50000
+   mmcif0   1   1   0   100000000   0     0  50000

On r8a77965/salvator-xs:

-   s0d3   1   2   0   266240000   0     0  50000
+   s0d3   2   2   0   266240000   0     0  50000

-   sys-dmac0   0   1   0   266240000   0     0  50000
+   sys-dmac0   1   1   0   266240000   0     0  50000

Gr{oetje,eeting}s,

                        Geert


--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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