> > The SD Physical Layer Spec says the following: Since the SD Memory Card > shall support at least the two bus modes 1-bit or 4-bit width, then any SD > Card shall set at least bits 0 and 2 (SD_BUS_WIDTH="0101"). > > This change verifies the card has specified a bus width. > > AMD SDHC Device 7806 can get into a bad state after a card disconnect > where anything transferred via the DATA lines will always result in a > zero filled buffer. Currently the driver will continue without error if > the HC is in this condition. A block device will be created, but reading > from it will result in a zero buffer. This makes it seem like the SD > device has been erased, when in actuality the data is never getting > copied from the DATA lines to the data buffer. > > SCR is the first command in the SD initialization sequence that uses the > DATA lines. By checking that the response was invalid, we can abort > mounting the card. > > Acked-by: Avri Altman <avri.alt...@wdc.com> > > Signed-off-by: Raul E Rangel <rran...@chromium.org> Reviewed-by: Avri Altman <avri.alt...@wdc.com>
Thanks, Avri
