mmc: warn about voltage mismatches

Get rid of a silent failure mode when the MMC/SD host doesn't
support the voltages needed to operate a given card, by
adding a warning.  A 3.3V host and a 3.0V card, for example,
no longer need to mysteriously just not work at all.

This isn't the best diagnostic; ideally it would also tell
what voltage the card and host support (and not just by
dumping the bitmasks).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This commit is contained in:
David Brownell 2008-12-31 09:50:30 -08:00 committed by Pierre Ossman
parent 9c43df5791
commit f6e10b865c

View file

@ -542,6 +542,8 @@ u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
host->ios.vdd = bit;
mmc_set_ios(host);
} else {
pr_warning("%s: host doesn't support card's voltages\n",
mmc_hostname(host));
ocr = 0;
}