[PATCH 4.8 126/140] mmc: core: switch to 1V8 or 1V2 for hs400es mode

From: Greg Kroah-Hartman
Date: Wed Oct 26 2016 - 09:08:11 EST


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

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

From: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>

commit 1720d3545b772c49b2975eeb3b8f4d3f56dc2085 upstream.

When introducing hs400es, I didn't notice that we haven't
switched voltage to 1V2 or 1V8 for it. That happens to work
as the first controller claiming to support hs400es, arasan(5.1),
which is designed to only support 1V8. So the voltage is fixed to 1V8.
But it actually is wrong, and will not fit for other host controllers.
Let's fix it.

Fixes: commit 81ac2af65793ecf ("mmc: core: implement enhanced strobe support")
Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/mmc/core/mmc.c | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1259,6 +1259,16 @@ static int mmc_select_hs400es(struct mmc
goto out_err;
}

+ if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400_1_2V)
+ err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120);
+
+ if (err && card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400_1_8V)
+ err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180);
+
+ /* If fails try again during next card power cycle */
+ if (err)
+ goto out_err;
+
err = mmc_select_bus_width(card);
if (err < 0)
goto out_err;