In the latest releases of the mmc driver, the freq during initialization
is set to a fixed 400 Khz. This was reportedly too fast for several
users. As there doesn't seem to be an ideal frequency
which-works-for-all, Pierre suggested to let the driver try several
frequencies.
This patch implements that idea. It will try mmc-initialization using
several frequencies from an array 400, 300, 200 and 100.
In case SDIO is broken, it'll still try to detect SDMEM, also at different
freqs.
Signed-off-by: Hein Tibosch <hein_tibosch@yahoo.es> Cc: Pierre Ossman <pierre@ossman.eu> Reviewed-by: Chris Ball <cjb@laptop.org> Tested-by: Chris Ball <cjb@laptop.org> Cc: Ben Nizette <bn@niasdigital.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Adrian Hunter <adrian.hunter@nokia.com> Cc: Matt Fleming <matt@console-pimps.org> Cc: <linux-mmc@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Chris Ball <cjb@laptop.org>