[PATCHv2 1/2] ARM: dts: socfpga: Fix SD card detect

[Doug Anderson]

Mark,

On Mon, Oct 20, 2014 at 11:41 AM, Mark Rutland <mark.rutland at arm.com> wrote:
> On Mon, Oct 20, 2014 at 04:31:18PM +0100, dinguyen at opensource.altera.com wrote:
>> From: Dinh Nguyen <dinguyen at opensource.altera.com>
>>
>> Without this patch, the booting the SOCFPGA platform would hang at the
>> SDMMC driver loading. There were 2 patches that caused this to happen:
>>
>> - Patch 9795a846e10 "mmc: dw_mmc: remove dw_mci_of_cd_gpio/wp_gpio()" removed
>>   looking for "cd-gpios", since mmc_of_parse was getting called.
>> - Patch 3cf890fc42b "mmc: dw_mmc: Pass back errors from mmc_of_parse()" would
>>   hang the system at the SDMMC driver loading.
>
> Regardless of which patches caused the issue, the existing DTB should
> continue to function. This is a kernel bug, not a DTB bug.

Right.  The kernel bug is that there is no "dtb fixup" stage of the
kernel to fix up old dtbs with this dtb bug.

Said another way:

1. The old dtb was (possibly) not specifying the cd-gpio properly.

2. The kernel had a bug where it was ignoring that error.  Things may
have been working because of some other side effect (maybe polling was
working).

3. If we fix the kernel bug, what should we do?  The only sensible
thing (if we need to support old DTB with no changes) is to add a DTB
fixup stage.

...or did someone add that stage and I missed it?

-Doug