[patch 2.6.28] mmc: warn about voltage mismatches
From: David Brownell
Date: Wed Dec 31 2008 - 12:50:46 EST
From: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/mmc/core/core.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -467,6 +467,8 @@ u32 mmc_select_voltage(struct mmc_host *
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;
}
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