Patch "mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:

     mmc-sdhci-of-at91-fix-mmc_ddr_52-timing-selection.patch

and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Ludovic Desroches <[email protected]>
Date: Tue, 28 Mar 2017 11:00:45 +0200
Subject: mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection

From: Ludovic Desroches <[email protected]>

commit d0918764c17b94c30bbb2619929b1719ff52707a upstream.

The controller has different timings for MMC_TIMING_UHS_DDR50 and MMC_TIMING_MMC_DDR52. Configuring the controller with SDHCI_CTRL_UHS_DDR50, when MMC_TIMING_MMC_DDR52 timings are requested, is not correct and can lead to unexpected behavior.

---
 drivers/mmc/host/sdhci-of-at91.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

@@ -29,6 +29,8 @@
 
 #include "sdhci-pltfm.h"
 
+#define SDMMC_MC1R	0x204
+#define		SDMMC_MC1R_DDR		BIT(3)
 #define SDMMC_CACR	0x230
 #define		SDMMC_CACR_CAPWREN	BIT(0)
 #define		SDMMC_CACR_KEY		(0x46 << 8)

@@ -103,11 +105,18 @@ static void sdhci_at91_set_power(struct
 	sdhci_set_power_noreg(host, mode, vdd);
 }
 
+void sdhci_at91_set_uhs_signaling(struct sdhci_host *host, unsigned int timing)
+{
+	if (timing == MMC_TIMING_MMC_DDR52)
+		sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R);
+	sdhci_set_uhs_signaling(host, timing);
+}
+
 static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
 	.set_clock		= sdhci_at91_set_clock,
 	.set_bus_width		= sdhci_set_bus_width,
 	.reset			= sdhci_reset,
-	.set_uhs_signaling	= sdhci_set_uhs_signaling,
+	.set_uhs_signaling	= sdhci_at91_set_uhs_signaling,
 	.set_power		= sdhci_at91_set_power,
 };
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/mmc-sdhci-of-at91-fix-mmc_ddr_52-timing-selection.patch