queue-4.14/arm-dts-am57xx-idk-remove-support-for-voltage-switching-for-sd-card.patch

   1 From 88a748419b84187fd1da05637b8e5928b04a1e06 Mon Sep 17 00:00:00 2001
   2 From: Faiz Abbas <faiz_abbas@ti.com>
   3 Date: Thu, 2 May 2019 14:17:48 +0530
   4 Subject: ARM: dts: am57xx-idk: Remove support for voltage switching for SD card
   5
   6 From: Faiz Abbas <faiz_abbas@ti.com>
   7
   8 commit 88a748419b84187fd1da05637b8e5928b04a1e06 upstream.
   9
  10 If UHS speed modes are enabled, a compatible SD card switches down to
  11 1.8V during enumeration. If after this a software reboot/crash takes
  12 place and on-chip ROM tries to enumerate the SD card, the difference in
  13 IO voltages (host @ 3.3V and card @ 1.8V) may end up damaging the card.
  14
  15 The fix for this is to have support for power cycling the card in
  16 hardware (with a PORz/soft-reset line causing a power cycle of the
  17 card). Since am571x-, am572x- and am574x-idk don't have this
  18 capability, disable voltage switching for these boards.
  19
  20 The major effect of this is that the maximum supported speed
  21 mode is now high speed(50 MHz) down from SDR104(200 MHz).
  22
  23 Cc: <stable@vger.kernel.org>
  24 Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
  25 Signed-off-by: Tony Lindgren <tony@atomide.com>
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  27
  28 ---
  29  arch/arm/boot/dts/am57xx-idk-common.dtsi |    1 +
  30  1 file changed, 1 insertion(+)
  31
  32 --- a/arch/arm/boot/dts/am57xx-idk-common.dtsi
  33 +++ b/arch/arm/boot/dts/am57xx-idk-common.dtsi
  34 @@ -405,6 +405,7 @@
  35         vqmmc-supply = <&ldo1_reg>;
  36         bus-width = <4>;
  37         cd-gpios = <&gpio6 27 GPIO_ACTIVE_LOW>; /* gpio 219 */
  38 +       no-1-8-v;
  39  };
  40
  41  &mmc2 {