From mboxrd@z Thu Jan 1 00:00:00 1970 From: heiko@sntech.de (Heiko =?ISO-8859-1?Q?St=FCbner?=) Date: Sun, 21 Dec 2014 15:04:13 +0100 Subject: [PATCH] ARM: dts: Bump SD card pin drive strength up on rk3288-evb In-Reply-To: <1418244929-8254-1-git-send-email-dianders@chromium.org> References: <1418244929-8254-1-git-send-email-dianders@chromium.org> Message-ID: <2971473.Y1akaDeraL@phil> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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