Re: mmc vs highmem, was: Re: [PATCH 2/2] blk-mq: ensure a q_usage_counter reference is held when splitting bios

Arnd Bergmann
2024-01-24T12:55:58Z

On Wed, Jan 24, 2024, at 13:33, Linus Walleij wrote:
> On Wed, Jan 24, 2024 at 12:59 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
>> Let's use your initial suggestion then and use a Kconfig
>> dependency.
>
> I'm looking into this.
>
>> I still don't like how this may impact users that
>> currently enable highmem and use one of these drivers,
>
> I'm taking it on a machine-by-machine basis.
>
> For example it
> turns out all OMAP2 that use mmci-omap are Nokia n800, n810
> and the H4 reference design.
>
> So I am seeing if these can be excluded from the "most omap2plus
> systems" list.

Unfortunately excluding Nokia n8x0 would turn the omap2plus
defconfig into an omap3plus_defconfig effectively.

This is also something that has come up repeatedly in the
past though: omap24xx (and imx31 to a lesser degree) support
in multiplatform kernels is really annoying because it
requires a lot of special cases to also work on SMP enabled
machines, and it completely breaks on ARMv8-aarch32 machines.

Arnd