[U-Boot] [PATCH] imx: mx6sxsabresd: support emmc

Stefano Babic
2016-01-24T13:53:41Z

Hi Peng,

On 24/01/2016 14:04, Peng Fan wrote:

>> I agree with Otavio that this is a very nasty hack, and the hardware
>> developer should provide a way getting the board revision. Anyway, I
>> would not certainly block it, as it concerns just this board, but I ask
>> if it is not better to let decide to an environment variable if eMMC
>> must be activated. Advantage is to have a single U-Boot binary for both
>> boards, disadvantage is that it coul be set for the wrong board
>> revision, too. But if USDHC4 was not used anymore, this drives just to a
>> not found eMMC. Both ways are hacks, I fully agree, but
>> CONFIG_MX6SXSABRESD_EMMC_REWORK remains undocumented at all, too.
>>
>> What do you think ?
>
> There is no fuse bit or else to let uboot do runtime checking. I also
> disklike this, but I do not have a better idea. Without runtime checking,
> it's hard to use one image support SD/EMMC both. I would like to
> add doc for the macro CONFIG_MX6SXSABRESD_EMMC_REWORK in the next version, do you agree with
> this?

I add Fabio as he is the board maintainer for mx6sxsabresd.

If adding the #ifdef remains the preferred solution instead of checkin
an env variable, it should be done that it does not generate dead code
as the current patch. That means that a defconfig file must be added
into configs, where CONFIG_MX6SXSABRESD_EMMC_REWORK is set. Else the
code is never built by running buildman and breakages cannot be detected.

Anyway, there are already two files for the board,
mx6sxsabresd_defconfig and mx6sxsabresd_spl_defconfig, and if you want
to have for this board revision both U-Boot with and without SPL, two
additional files are needed - it does not scale very well.

Best regards,
Stefano Babic

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