From f6e10b865c3ea56bdaa8c6ecfee313b997900dbb Mon Sep 17 00:00:00 2001
From: David Brownell <dbrownell@users.sourceforge.net>
Date: Wed, 31 Dec 2008 09:50:30 -0800
Subject: [PATCH] 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>
---
drivers/mmc/core/core.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 5f288aeeb721..df6ce4a06cf3 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -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;
}
--
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