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authorUlf Hansson <ulf.hansson@linaro.org>2019-08-27 10:10:43 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-09-06 10:19:51 +0200
commitc7ed5c02e4101faef5e9d542aa3da4c4d63acaae (patch)
treec4f5346cd13ceebba8ac34752f57751c4cffdb3d
parentf0d3242a1211c2f12a6da93c97e6b2c4861aba88 (diff)
mmc: core: Fix init of SD cards reporting an invalid VDD range
commit 72741084d903e65e121c27bd29494d941729d4a1 upstream. The OCR register defines the supported range of VDD voltages for SD cards. However, it has turned out that some SD cards reports an invalid voltage range, for example having bit7 set. When a host supports MMC_CAP2_FULL_PWR_CYCLE and some of the voltages from the invalid VDD range, this triggers the core to run a power cycle of the card to try to initialize it at the lowest common supported voltage. Obviously this fails, since the card can't support it. Let's fix this problem, by clearing invalid bits from the read OCR register for SD cards, before proceeding with the VDD voltage negotiation. Cc: stable@vger.kernel.org Reported-by: Philip Langdale <philipl@overt.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Philip Langdale <philipl@overt.org> Tested-by: Philip Langdale <philipl@overt.org> Tested-by: Manuel Presnitz <mail@mpy.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/mmc/core/sd.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 00ba8807dafe..7f654c714fff 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1259,6 +1259,12 @@ int mmc_attach_sd(struct mmc_host *host)
goto err;
}
+ /*
+ * Some SD cards claims an out of spec VDD voltage range. Let's treat
+ * these bits as being in-valid and especially also bit7.
+ */
+ ocr &= ~0x7FFF;
+
rocr = mmc_select_voltage(host, ocr);
/*