[PATCH 4.9 11/93] mmc: core: Fix access to HS400-ES devices

From: Greg Kroah-Hartman
Date: Wed Aug 09 2017 - 14:32:45 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Guenter Roeck <linux@xxxxxxxxxxxx>

commit 773dc118756b1f38766063e90e582016be868f09 upstream.

HS400-ES devices fail to initialize with the following error messages.

mmc1: power class selection to bus width 8 ddr 0 failed
mmc1: error -110 whilst initialising MMC card

This was seen on Samsung Chromebook Plus. Code analysis points to
commit 3d4ef329757c ("mmc: core: fix multi-bit bus width without
high-speed mode"), which attempts to set the bus width for all but
HS200 devices unconditionally. However, for HS400-ES, the bus width
is already selected.

Cc: Anssi Hannula <anssi.hannula@xxxxxxxxxx>
Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
Cc: Brian Norris <briannorris@xxxxxxxxxxxx>
Fixes: 3d4ef329757c ("mmc: core: fix multi-bit bus width ...")
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Reviewed-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxx>
Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/mmc/core/mmc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1690,7 +1690,7 @@ static int mmc_init_card(struct mmc_host
err = mmc_select_hs400(card);
if (err)
goto free_card;
- } else {
+ } else if (!mmc_card_hs400es(card)) {
/* Select the desired bus width optionally */
err = mmc_select_bus_width(card);
if (err > 0 && mmc_card_hs(card)) {