[U-Boot] [PATCH 4/5] mmc: tegra: allow disabling external clock loopback

[Marcel Ziswiler]

On December 1, 2016 3:20:55 AM GMT+01:00, Simon Glass <sjg at chromium.org> wrote:
>Hi Marcel,
>
>On 30 November 2016 at 09:47, Marcel Ziswiler <marcel at ziswiler.com>
>wrote:
>> From: Marcel Ziswiler <marcel.ziswiler at toradex.com>
>>
>> Introduce CONFIG_TEGRA124_MMC_DISABLE_EXT_LOOPBACK to disable the
>external clock
>> loopback and use the internal one on SDMMC3 as per the
>SDMMC_VENDOR_MISC_CNTRL_0
>> register's SDMMC_SPARE1 bits being set to 0xfffd according to the
>TRM.
>>
>> Signed-off-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>
>> ---
>>
>>  arch/arm/include/asm/arch-tegra/tegra_mmc.h |  2 ++
>>  drivers/mmc/Kconfig                         |  8 ++++++++
>>  drivers/mmc/tegra_mmc.c                     | 13 +++++++++++++
>>  3 files changed, 23 insertions(+)
>
>This should be controlled by the device tree, shouldn't it?

Glad you brought it up. So far NVIDIA hasn't even acknowledged that they completely seriously screwed this one up big time. Unlike their PCIe bug I reported which eventually did make it to the errata... Anyway, my hopes were kind of to sneak this one into U-Boot first, then work on a proper kernel integration probably involving device tree integration and only in a later third step maybe updating this in U-Boot again.

>Regards,
>Simon

Cheers

Marcel