[GIT PULL] ARM: SoC fixes for v5.10, part 3

[Arnd Bergmann]

On Mon, Dec 7, 2020 at 9:23 PM Geert Uytterhoeven <geert at linux-m68k.org> wrote:
> On Tue, Dec 1, 2020 at 3:06 PM Arnd Bergmann <arnd at kernel.org> wrote:
> > On Tue, Dec 1, 2020 at 12:39 PM Ulf Hansson <ulf.hansson at linaro.org> wrote:
> > > So, I think we have two options. If people are willing to move to
> > > "disk labels" or to patch their DTBs with mmc aliases, things can stay
> > > as is. Otherwise, we can revert the async probe parts of the mmc host
> > > drivers, but that would still leave us in a fragile situation.
> >
> > Can you reliably detect whether the mmc aliases in the dt exist?
> > If that's possible, maybe the async flag could be masked out to only have
> > an effect when the device number is known.
>
> IMHO DT aliases are not a proper solution for this.
>
> Yes, you can detect reliably if an alias exists in the DT.
> The problems start when having multiple devices, some with aliases,
> some without.  And when devices can appear dynamically (without
> aliases, as there is no support for dynamically updating the aliases
> list).

Actually you hit a problem earlier than that: the async probe is a
property of the host controller driver, which may be a pci_driver,
platform_driver, usb_driver, or anything else really. To figure out
whether to probe it asynchronously, it would have to be the driver
core, or each bus type that can host these to understand which
device driver is responsible for probing an eMMC device attached
to the host.

       Arnd