From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Sat, 19 Nov 2011 12:36:00 -0700 Subject: [U-Boot] Revert "mmc: retry the cmd8 to meet 74 clocks requirement in the spec" In-Reply-To: <1321349739-15212-1-git-send-email-macpaul@andestech.com> References: <1321349739-15212-1-git-send-email-macpaul@andestech.com> Message-ID: <4EC80520.3030307@nvidia.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 01/-10/-28163 12:59 PM, Macpaul Lin wrote: > This reverts commit 02f3029f1810b99869254d0cf0a71946a008a728. > > This patch add 3 times retry to CMD8 because the Marvell mmc controller > doesn't obey the power ramp up process in the SD specification 6.4.1. > (Please refer to figure 6.1 and 6.2 in the specification.) > > The CMD0 should be send after power ramp up has been finished. > However, the Marvell mmc contorller must do power ramp up after the > first CMD0 command has been send. > > This patch also affect existing platforms like Nokia N900 and other > platforms. > > Signed-off-by: Macpaul Lin > Acked-by: Lei Wen Acked-by: Stephen Warren Tested-by: Stephen Warren As background, I'm working on patches to support the Toshiba AC100 / Dynabook AZ in mainline U-Boot. The internal MMC didn't work at all until this revert was applied. The SD slot worked perfectly though. I guess this is related to the MMC itself not supporting this (SD-specific?) command, and the patch caused MMC mode never to be attempted.