From: Philip Rakity Date: Wed, 25 May 2011 01:14:58 +0000 (-0700) Subject: mmc: core: eMMC bus width may not work on all platforms X-Git-Tag: v3.0-rc1~148^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=08ee80cc397ac1a306ca689a22ede954d92d0db1;p=pandora-kernel.git mmc: core: eMMC bus width may not work on all platforms CMD19 -- The offical way to validate bus widths from the JEDEC spec does not work on all platforms. Some platforms that use PCI/PCIe to connect their SD controllers are known to fail. If the quirk MMC_BUS_WIDTH_TEST is not defined we try to figure out the bus width by reading the ext_csd at different bus widths and compare this against the ext_csd read in 1 bit mode. If no ext_csd is available we default to 1 bit operations. Code has been tested on mmp2 against 8 bit eMMC and Transcend 2GB card that is known to not work in 4 bit mode. The physical pins on the card are not present to support 4 bit operation. Signed-off-by: Philip Rakity Signed-off-by: Chris Ball --- Reading git-diff-tree failed