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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 10:18:17 +0200
commite2f1509fca476d763d94eb0026b28c22ab110688 (patch)
tree98cfccd7d011e62a6f06623b7de6ad11aeddae16
parent12a897daa78b640bcdfd6422bf2d697c442549e1 (diff)
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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 fb8741f18c1f..54ba1abb5460 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1232,6 +1232,12 @@ 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);
/*