Commit 6e1c7d61 authored by Adrian Hunter's avatar Adrian Hunter Committed by Ulf Hansson
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mmc: sdhci-acpi: Reduce Baytrail eMMC/SD/SDIO hangs 



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: default avatarAdrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent c3b46c73

drivers/mmc/host/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/mmc/host/sdhci-acpi.c

+81 −0
Original line number Diff line number Diff line
@@ -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 {
@@ -116,6 +121,75 @@ static const struct sdhci_acpi_chip sdhci_acpi_chip_int = { 
	.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, MBI_CR_READ, 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, MBI_CR_WRITE, 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);
@@ -322,6 +396,9 @@ static int sdhci_acpi_probe(struct platform_device *pdev) 
	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;
@@ -447,6 +524,8 @@ static int sdhci_acpi_resume(struct device *dev) 
{

	struct sdhci_acpi_host *c = dev_get_drvdata(dev);



	sdhci_acpi_byt_setting(&c->pdev->dev);



	return sdhci_resume_host(c->host);

}
@@ -470,6 +549,8 @@ static int sdhci_acpi_runtime_resume(struct device *dev) 
{

	struct sdhci_acpi_host *c = dev_get_drvdata(dev);



	sdhci_acpi_byt_setting(&c->pdev->dev);



	return sdhci_runtime_resume_host(c->host);

}

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