[PATCH] mmc: don't print 'MMC:' if there are no MMC devices

[Caleb Connolly]

On 13/11/2024 15:24, Tom Rini wrote:
> On Wed, Nov 13, 2024 at 06:30:08AM +0100, Caleb Connolly wrote:
> 
>> It may be the case that MMC support is enabled even though the board
>> we're booting on doesn't have any MMC devices. Move the print over to
>> the print_mmc_devices() function where we can only print it if we
>> actually have MMC devices.
>>
>> Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
> 
> I'm not sure I like this. What we do / don't find on startup is part of
> the not-exactly-API. It's true that if we don't print an MMC line at
> all, and we should have MMC, the user (and any scripts that parse
> console output) but now we're also increasing the code size a little bit
> too. I can be convinced this is a good idea, but I'm not there yet.

Hmm, fair enough. I'll offer some more context, maybe there's a smarter
approach here I'm not seeing.

The main place this shows up is on Qualcomm boards. Since all Qualcomm
armv8 targets are supported with qcom_defconfig (just by adjusting which
DTB is used), we can't know at build time whether the board has MMC.

I guess my thinking behind this patch comes from a bigger picture desire
to get UFS and MMC more aligned. The number of devices with UFS is
definitely going up, and I would argue that U-Boot's inconsistent
treatment of these two storage classes (obviously a result of their
relative age and support in the codebase) is really unintuitive and
weird for users (nevermind that the "scsi" command is used for UFS
devices, cute though it is).

I'm really wary to open this whole can of worms, since I guess it would
require some larger efforts and collaboration to fix. But maybe this
patch (or one like it) would be better suited in the context of some
larger effort to unify storage backends?

Kind regards,
> 

-- 
// Caleb (they/them)