Some board configurations can not support sd highspeed mode due to the distance between the card slot and the controller. The card and controller report that they are capable of highspeed however, so we need a mechanism for specifying that the setup is incapable of supporting highspeed mode.
The first patch adds documentation about a new devicetree property sd-broken-highspeed. The second patch keeps the sd controller and card from going into highspeed mode when the property is set. v2: * changed sd-broken-highspeed to broken-highspeed * Removed new quirk, instead read of property when would've checked quirk Zach Brown (2): sdhci: Add device tree property broken-highspeed sdhci: Prevent SD from doing high-speed timing when broken-highspeed property is set Documentation/devicetree/bindings/mmc/mmc.txt | 2 ++ drivers/mmc/host/sdhci.c | 4 +++- 2 files changed, 5 insertions(+), 1 deletion(-) -- 2.7.4