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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