From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Szyprowski Subject: Re: [PATCH 0/2] Fix reboot issue on Odroid boards with eMMC card Date: Tue, 27 Jan 2015 14:29:08 +0100 Message-ID: <54C792A4.3040302@samsung.com> References: <1422346289-9348-1-git-send-email-m.szyprowski@samsung.com> <1422348967.10070.26.camel@collabora.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <1422348967.10070.26.camel-ZGY8ohtN/8pPYcu2f3hruQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sjoerd Simons Cc: linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-samsung-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Kukjin Kim , Tobias Jakobi , Daniel Drake , Sebastian Reichel , Seungwon Jeon , Jaehoon Chung , Ulf Hansson , Joonyoung Shim List-Id: linux-pm@vger.kernel.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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html