Patch "mmc: sdhci-of-esdhc: fixup PRESENT_STATE read" has been added to the 4.8-stable tree

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

mmc: sdhci-of-esdhc: fixup PRESENT_STATE read

to the 4.8-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-esdhc-fixup-present_state-read.patch
and it can be found in the queue-4.8 subdirectory.

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

From: Michael Walle <[email protected]>
Date: Tue, 15 Nov 2016 11:13:16 +0100
Subject: mmc: sdhci-of-esdhc: fixup PRESENT_STATE read

From: Michael Walle <[email protected]>

commit b0921d5c9ed6ffa8a4d6afc5ee5f136b87445f14 upstream.

Since commit 87a18a6a5652 ("mmc: mmc: Use ->card_busy() to detect busy cards in __mmc_switch()") the ESDHC driver is broken:
mmc0: Card stuck in programming state! __mmc_switch
mmc0: error -110 whilst initialising MMC card

Since this commit __mmc_switch() uses ->card_busy(), which is sdhci_card_busy() for the esdhc driver. sdhci_card_busy() uses the PRESENT_STATE register, specifically the DAT0 signal level bit. But the ESDHC uses a non-conformant PRESENT_STATE register, thus a read fixup is required to make the driver work again.

---
 drivers/mmc/host/sdhci-of-esdhc.c |   14 ++++++++++++++
 drivers/mmc/host/sdhci.h          |    1 +
 2 files changed, 15 insertions(+)

@@ -66,6 +66,20 @@ static u32 esdhc_readl_fixup(struct sdhc
 			return ret;
 		}
 	}
+	/*
+	 * The DAT[3:0] line signal levels and the CMD line signal level are
+	 * not compatible with standard SDHC register. The line signal levels
+	 * DAT[7:0] are at bits 31:24 and the command line signal level is at
+	 * bit 23. All other bits are the same as in the standard SDHC
+	 * register.
+	 */
+	if (spec_reg == SDHCI_PRESENT_STATE) {
+		ret = value & 0x000fffff;
+		ret |= (value >> 4) & SDHCI_DATA_LVL_MASK;
+		ret |= (value << 1) & SDHCI_CMD_LVL;
+		return ret;
+	}
+
 	ret = value;
 	return ret;
 }

@@ -73,6 +73,7 @@
 #define  SDHCI_DATA_LVL_MASK	0x00F00000
 #define   SDHCI_DATA_LVL_SHIFT	20
 #define   SDHCI_DATA_0_LVL_MASK	0x00100000
+#define  SDHCI_CMD_LVL		0x01000000
 
 #define SDHCI_HOST_CONTROL	0x28
 #define  SDHCI_CTRL_LED		0x01

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

queue-4.8/mmc-sdhci-of-esdhc-fixup-present_state-read.patch