Hi Ulf,
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)
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
