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
......@@ -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
......
......@@ -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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