[PATCH 4.5 108/200] mmc: sdhci-acpi: Reduce Baytrail eMMC/SD/SDIO hangs

Greg Kroah-Hartman
2016-05-03T01:08:55Z

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>
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, 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);
@@ -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);
}