linux/include
Daniel Drake 6a66180a25 mmc: sdhci: add quirk for lack of 1.8v support
The OLPC XO-1.75 laptop includes a SDHCI controller which is 1.8v
capable, and it truthfully reports so in its capabilities. This
alternate voltage is used for driving new "UHS-I" SD cards at their
full speed.

However, what the controller doesn't know is that the motherboard
physically doesn't have a 1.8v supply available.

Add a quirk so that systems such as this one can override disable
1.8v support, adding support for UHS-I cards (by running them at
3.3v).

This avoids a problem where the system would first try to run the
card at 1.8v, fail, and then not be able to fully reset the card
to retry at the normal 3.3v voltage.

This is more appropriate than using the MISSING_CAPS quirk, which
is intended for cases where the SDHCI controller is actually lying
about its capabilities, and would force us to somehow override both
caps words from another source.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Reviewed-by: Philip Rakity <prakity@nvidia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-12-06 13:55:04 -05:00
..
acpi
asm-generic Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2012-10-14 14:39:05 -07:00
clocksource
crypto Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
drm
keys
linux mmc: sdhci: add quirk for lack of 1.8v support 2012-12-06 13:55:04 -05:00
math-emu
media
memory
misc
mtd UAPI: (Scripted) Disintegrate include/mtd 2012-10-09 09:49:09 +01:00
net
pcmcia
ras
rdma
rxrpc
scsi SCSI misc on 20121012 2012-10-13 10:57:01 +09:00
sound
target
trace Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2012-10-10 10:49:20 +09:00
uapi UAPI Disintegration 2012-10-13 2012-10-13 13:28:32 -07:00
video fbdev updates for 3.7 2012-10-12 10:21:02 +09:00
xen UAPI Disintegration 2012-10-09 2012-10-13 11:14:29 +09:00
Kbuild