[RFT] arm64: dts: renesas: salvator-common: enable SDR104 for SD cards

From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-renesas-soc@vger.kernel.org
Cc: linux-mmc@vger.kernel.org, Simon Horman <horms@verge.net.au>,
	Wolfram Sang <wsa+renesas@sang-engineering.com>
Subject: [RFT] arm64: dts: renesas: salvator-common: enable SDR104 for SD cards
Date: Wed,  2 Aug 2017 22:13:11 +0200	[thread overview]
Message-ID: <20170802201311.1394-1-wsa+renesas@sang-engineering.com> (raw)

Tests showed that SDHI driver problems have been solved and SDR104 works
now reliably on both Salvator-X SD card slots, both with an R-Car H3
(r8a7795 ES1.0) and R-Car M3 (r8a7796 ES 1.0). So, finally, enable it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Awesome, awesome! For the last two days, I did various tests with my boards and
SD cards and SDR104 worked absolutely reliably :D Even the problematic card I
had works flawlessly. I couldn't trigger the known failures anymore. Although I
tried, I can't point to a single patch which "fixed" the issue. It is the
constant work on dealing with smaller issues which makes SDR104 work at the end
of the day. However, two patches are likely a bigger part of the cake:

43b0b361b01700 ("mmc: tmio: always get number of taps")
-> Already upstream. This fixed retuning on card changes.

85b81aa16ec4ed ("mmc: tmio: fix CMD12 (STOP) handling")
-> In mmc/next. This allows to handle tuning errors gracefully and to retune.

With the freshly submitted Gen3 DMA patches, we also get nice transfer speeds :)

This patch is based on renesas-drivers/master as of today. A branch for testing
can be found here:

git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git renesas/v8-sdr104

All patches needed for reliable SDR104 are already upstream or in mmc/next. The
above branch only adds another patch to enable DMA on Gen3. It is not strictly
needed, but very nice to have. I think it would be cool to get both patches
into v4.14.

Looking forward to other testers. Simon, do you have some time for this?

Thanks and kind regards,

  a very happy Wolfram


 arch/arm64/boot/dts/renesas/salvator-common.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/renesas/salvator-common.dtsi b/arch/arm64/boot/dts/renesas/salvator-common.dtsi
index a451996f590a51..18e2da9f866684 100644
--- a/arch/arm64/boot/dts/renesas/salvator-common.dtsi
+++ b/arch/arm64/boot/dts/renesas/salvator-common.dtsi
@@ -569,6 +569,7 @@
 	wp-gpios = <&gpio3 13 GPIO_ACTIVE_HIGH>;
 	bus-width = <4>;
 	sd-uhs-sdr50;
+	sd-uhs-sdr104;
 	status = "okay";
 };
 
@@ -597,6 +598,7 @@
 	wp-gpios = <&gpio4 16 GPIO_ACTIVE_HIGH>;
 	bus-width = <4>;
 	sd-uhs-sdr50;
+	sd-uhs-sdr104;
 	status = "okay";
 };
 
-- 
2.11.0
