Patch "mmc: sdhci-acpi: Reduce Baytrail eMMC/SD/SDIO hangs" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    mmc: sdhci-acpi: Reduce Baytrail eMMC/SD/SDIO hangs

to the 4.4-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-acpi-reduce-baytrail-emmc-sd-sdio-hangs.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 6e1c7d6103fe7031035cec321307c6356809adf4 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@intel.com>
Date: Fri, 15 Apr 2016 14:06:57 +0300
Subject: mmc: sdhci-acpi: Reduce Baytrail eMMC/SD/SDIO hangs

From: Adrian Hunter <adrian.hunter@intel.com>

commit 6e1c7d6103fe7031035cec321307c6356809adf4 upstream.

Baytrail eMMC/SD/SDIO host controllers have been known to
hang.  A change to a hardware setting has been found to
reduce the occurrence of such hangs.  This patch ensures
the correct setting.

This patch applies cleanly to v4.4+.  It could go to
earlier kernels also, so I will send backports to the
stable list in due course.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/mmc/host/Kconfig      |    1 
 drivers/mmc/host/sdhci-acpi.c |   81 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 82 insertions(+)

--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -97,6 +97,7 @@ config MMC_RICOH_MMC
 config MMC_SDHCI_ACPI
 	tristate "SDHCI support for ACPI enumerated SDHCI controllers"
 	depends on MMC_SDHCI && ACPI
+	select IOSF_MBI if X86
 	help
 	  This selects support for ACPI enumerated SDHCI controllers,
 	  identified by ACPI Compatibility ID PNP0D40 or specific
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -41,6 +41,11 @@
 #include <linux/mmc/pm.h>
 #include <linux/mmc/slot-gpio.h>
 
+#ifdef CONFIG_X86
+#include <asm/cpu_device_id.h>
+#include <asm/iosf_mbi.h>
+#endif
+
 #include "sdhci.h"
 
 enum {
@@ -146,6 +151,75 @@ static const struct sdhci_acpi_chip sdhc
 	.ops = &sdhci_acpi_ops_int,
 };
 
+#ifdef CONFIG_X86
+
+static bool sdhci_acpi_byt(void)
+{
+	static const struct x86_cpu_id byt[] = {
+		{ X86_VENDOR_INTEL, 6, 0x37 },
+		{}
+	};
+
+	return x86_match_cpu(byt);
+}
+
+#define BYT_IOSF_SCCEP			0x63
+#define BYT_IOSF_OCP_NETCTRL0		0x1078
+#define BYT_IOSF_OCP_TIMEOUT_BASE	GENMASK(10, 8)
+
+static void sdhci_acpi_byt_setting(struct device *dev)
+{
+	u32 val = 0;
+
+	if (!sdhci_acpi_byt())
+		return;
+
+	if (iosf_mbi_read(BYT_IOSF_SCCEP, 0x06, BYT_IOSF_OCP_NETCTRL0,
+			  &val)) {
+		dev_err(dev, "%s read error\n", __func__);
+		return;
+	}
+
+	if (!(val & BYT_IOSF_OCP_TIMEOUT_BASE))
+		return;
+
+	val &= ~BYT_IOSF_OCP_TIMEOUT_BASE;
+
+	if (iosf_mbi_write(BYT_IOSF_SCCEP, 0x07, BYT_IOSF_OCP_NETCTRL0,
+			   val)) {
+		dev_err(dev, "%s write error\n", __func__);
+		return;
+	}
+
+	dev_dbg(dev, "%s completed\n", __func__);
+}
+
+static bool sdhci_acpi_byt_defer(struct device *dev)
+{
+	if (!sdhci_acpi_byt())
+		return false;
+
+	if (!iosf_mbi_available())
+		return true;
+
+	sdhci_acpi_byt_setting(dev);
+
+	return false;
+}
+
+#else
+
+static inline void sdhci_acpi_byt_setting(struct device *dev)
+{
+}
+
+static inline bool sdhci_acpi_byt_defer(struct device *dev)
+{
+	return false;
+}
+
+#endif
+
 static int bxt_get_cd(struct mmc_host *mmc)
 {
 	int gpio_cd = mmc_gpio_get_cd(mmc);
@@ -337,6 +411,9 @@ static int sdhci_acpi_probe(struct platf
 	if (acpi_bus_get_status(device) || !device->status.present)
 		return -ENODEV;
 
+	if (sdhci_acpi_byt_defer(dev))
+		return -EPROBE_DEFER;
+
 	hid = acpi_device_hid(device);
 	uid = device->pnp.unique_id;
 
@@ -460,6 +537,8 @@ static int sdhci_acpi_resume(struct devi
 {
 	struct sdhci_acpi_host *c = dev_get_drvdata(dev);
 
+	sdhci_acpi_byt_setting(&c->pdev->dev);
+
 	return sdhci_resume_host(c->host);
 }
 
@@ -483,6 +562,8 @@ static int sdhci_acpi_runtime_resume(str
 {
 	struct sdhci_acpi_host *c = dev_get_drvdata(dev);
 
+	sdhci_acpi_byt_setting(&c->pdev->dev);
+
 	return sdhci_runtime_resume_host(c->host);
 }
 


Patches currently in stable-queue which might be from adrian.hunter@intel.com are

queue-4.4/perf-intel-pt-fix-occasional-decoding-errors-when-tracing-system-wide.patch
queue-4.4/mmc-sdhci-acpi-reduce-baytrail-emmc-sd-sdio-hangs.patch