From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko =?ISO-8859-1?Q?St=FCbner?= Subject: Re: [PATCH] ARM: dts: Bump SD card pin drive strength up on rk3288-evb Date: Sun, 21 Dec 2014 15:04:13 +0100 Message-ID: <2971473.Y1akaDeraL@phil> References: <1418244929-8254-1-git-send-email-dianders@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <1418244929-8254-1-git-send-email-dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Doug Anderson Cc: Addy Ke , Jaehoon Chung , Seungwon Jeon , Ulf Hansson , Alim Akhtar , Sonny Rao , Andrew Bresticker , linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org Am Mittwoch, 10. Dezember 2014, 12:55:29 schrieb Doug Anderson: > It seems that ever since (536f6b9 mmc: dw_mmc: Reset DMA before > enabling IDMAC) landed upstream that SD cards have been very unhappy > on rk3288-evb. They were a little unhappy before that change, but > after that change they're REALLY unhappy. > > It turns out that the above fix happens to fix a corruption when > reading card information during probe time. Without the fix we didn't > detect that high speed SD cards could actually support high speed. > With the fix we suddenly detect that they're high speed and we try to > use them at 50MHz. That doesn't work so well on EVB with the default > drive strength (maybe because there are two physical SD card slots > hooked up to the same pin?). > > Fix the problem by bumping up the drive strength of the sdmmc lines. > > Signed-off-by: Doug Anderson > Fixes: 536f6b91d21b ("mmc: dw_mmc: Reset DMA before enabling IDMAC") applied to my 3.19 dts-fixes branch (after a slight modification of the subject: please use "ARM: dts: rockchip:") Heiko -- 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