Re: [PATCH 0/2] Fix reboot issue on Odroid boards with eMMC card

[Marek Szyprowski <m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>]

Hello,

On 2015-01-27 09:56, Sjoerd Simons wrote:
> On Tue, 2015-01-27 at 09:11 +0100, Marek Szyprowski wrote:
>> This patchset fixes reboot hang issue on Hardkernel's Odroid boards with
>> eMMC card. Those boards are designed in such a way, that the eMMC nreset
>> signal is routed to SoC GPIO line instead of the board reset logic. To
>> properly restard system, one need to set this line to zero before
>> performing reboot.
>>
>> The initial patches consisted of a complete reset/power off driver, but
>> after further analysis, it turned out that only eMMC nreset line control
>> logic is specific for those boards. Everything else can be done by
>> generic Exynos code, so the code has been moved to Exynos DW MMC driver.
> This seems a general board design quirk, rather then an exynos specific
> one. Potentially better to have this in the mmc core so it can be
> re-used by non-exynos boards?
>
> A very quick peek at the schematic for the hardkernel C1 (amlogic
> based), shows that for that board the eMMC reset line is hooked up to an
> SoC gpio line as well. (Although ofcourse, it may not need to be reset
> before a warm restart depending on what the amlogic rom code does).
>
>
> Random side-note, at least the samsung peach chromebooks are also hooked
> up this way. But don't run into this issue as they load their initial
> stages from flash rather then the eMMC.

Okay, I will try to move all the code to mmc core. I've also noticed that
sdhci-pci driver already implements hw_reset feature with gpio line, 
although
I cannot find any user of it (I cannot find any platform data provider for
sdhci-pci driver).

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

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