diff mbox

[v2] mmc: dw_mmc-exynos: fix potential external abort in resume_noirq()

Message ID 20180612105523.30243-1-m.szyprowski@samsung.com (mailing list archive)
State Not Applicable
Headers show

Commit Message

Marek Szyprowski June 12, 2018, 10:55 a.m. UTC
dw_mci_exynos_resume_noirq() performs DWMMC register access without
ensuring that respective clocks are enabled. This might cause external
abort on some systems (observed on Exynos5433 based boards). Fix this
by forcing a PM runtime active state before register access. Using
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS allows also to cleanup conditional code
a bit.

Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/mmc/host/dw_mmc-exynos.c | 33 +++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

Comments

Ulf Hansson July 2, 2018, 1:17 p.m. UTC | #1
On 12 June 2018 at 12:55, Marek Szyprowski <m.szyprowski@samsung.com> wrote:
> dw_mci_exynos_resume_noirq() performs DWMMC register access without
> ensuring that respective clocks are enabled. This might cause external
> abort on some systems (observed on Exynos5433 based boards). Fix this
> by forcing a PM runtime active state before register access. Using
> SET_NOIRQ_SYSTEM_SLEEP_PM_OPS allows also to cleanup conditional code
> a bit.
>
> Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

Thanks, applied for next!

Kind regards
Uffe

> ---
>  drivers/mmc/host/dw_mmc-exynos.c | 33 +++++++++++++++++++++++---------
>  1 file changed, 24 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
> index 3164681108ae..b430db905bb5 100644
> --- a/drivers/mmc/host/dw_mmc-exynos.c
> +++ b/drivers/mmc/host/dw_mmc-exynos.c
> @@ -175,6 +175,20 @@ static int dw_mci_exynos_runtime_resume(struct device *dev)
>
>         return ret;
>  }
> +#endif /* CONFIG_PM */
> +
> +#ifdef CONFIG_PM_SLEEP
> +/**
> + * dw_mci_exynos_suspend_noirq - Exynos-specific suspend code
> + *
> + * This ensures that device will be in runtime active state in
> + * dw_mci_exynos_resume_noirq after calling pm_runtime_force_resume()
> + */
> +static int dw_mci_exynos_suspend_noirq(struct device *dev)
> +{
> +       pm_runtime_get_noresume(dev);
> +       return pm_runtime_force_suspend(dev);
> +}
>
>  /**
>   * dw_mci_exynos_resume_noirq - Exynos-specific resume code
> @@ -186,12 +200,16 @@ static int dw_mci_exynos_runtime_resume(struct device *dev)
>   *
>   * We run this code on all exynos variants because it doesn't hurt.
>   */
> -
>  static int dw_mci_exynos_resume_noirq(struct device *dev)
>  {
>         struct dw_mci *host = dev_get_drvdata(dev);
>         struct dw_mci_exynos_priv_data *priv = host->priv;
>         u32 clksel;
> +       int ret;
> +
> +       ret = pm_runtime_force_resume(dev);
> +       if (ret)
> +               return ret;
>
>         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
>                 priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
> @@ -207,11 +225,11 @@ static int dw_mci_exynos_resume_noirq(struct device *dev)
>                         mci_writel(host, CLKSEL, clksel);
>         }
>
> +       pm_runtime_put(dev);
> +
>         return 0;
>  }
> -#else
> -#define dw_mci_exynos_resume_noirq     NULL
> -#endif /* CONFIG_PM */
> +#endif /* CONFIG_PM_SLEEP */
>
>  static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
>  {
> @@ -556,14 +574,11 @@ static int dw_mci_exynos_remove(struct platform_device *pdev)
>  }
>
>  static const struct dev_pm_ops dw_mci_exynos_pmops = {
> -       SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> -                               pm_runtime_force_resume)
> +       SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(dw_mci_exynos_suspend_noirq,
> +                                     dw_mci_exynos_resume_noirq)
>         SET_RUNTIME_PM_OPS(dw_mci_runtime_suspend,
>                            dw_mci_exynos_runtime_resume,
>                            NULL)
> -       .resume_noirq = dw_mci_exynos_resume_noirq,
> -       .thaw_noirq = dw_mci_exynos_resume_noirq,
> -       .restore_noirq = dw_mci_exynos_resume_noirq,
>  };
>
>  static struct platform_driver dw_mci_exynos_pltfm_driver = {
> --
> 2.17.1
>
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diff mbox

Patch

diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index 3164681108ae..b430db905bb5 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -175,6 +175,20 @@  static int dw_mci_exynos_runtime_resume(struct device *dev)
 
 	return ret;
 }
+#endif /* CONFIG_PM */
+
+#ifdef CONFIG_PM_SLEEP
+/**
+ * dw_mci_exynos_suspend_noirq - Exynos-specific suspend code
+ *
+ * This ensures that device will be in runtime active state in
+ * dw_mci_exynos_resume_noirq after calling pm_runtime_force_resume()
+ */
+static int dw_mci_exynos_suspend_noirq(struct device *dev)
+{
+	pm_runtime_get_noresume(dev);
+	return pm_runtime_force_suspend(dev);
+}
 
 /**
  * dw_mci_exynos_resume_noirq - Exynos-specific resume code
@@ -186,12 +200,16 @@  static int dw_mci_exynos_runtime_resume(struct device *dev)
  *
  * We run this code on all exynos variants because it doesn't hurt.
  */
-
 static int dw_mci_exynos_resume_noirq(struct device *dev)
 {
 	struct dw_mci *host = dev_get_drvdata(dev);
 	struct dw_mci_exynos_priv_data *priv = host->priv;
 	u32 clksel;
+	int ret;
+
+	ret = pm_runtime_force_resume(dev);
+	if (ret)
+		return ret;
 
 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
@@ -207,11 +225,11 @@  static int dw_mci_exynos_resume_noirq(struct device *dev)
 			mci_writel(host, CLKSEL, clksel);
 	}
 
+	pm_runtime_put(dev);
+
 	return 0;
 }
-#else
-#define dw_mci_exynos_resume_noirq	NULL
-#endif /* CONFIG_PM */
+#endif /* CONFIG_PM_SLEEP */
 
 static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
 {
@@ -556,14 +574,11 @@  static int dw_mci_exynos_remove(struct platform_device *pdev)
 }
 
 static const struct dev_pm_ops dw_mci_exynos_pmops = {
-	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
-				pm_runtime_force_resume)
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(dw_mci_exynos_suspend_noirq,
+				      dw_mci_exynos_resume_noirq)
 	SET_RUNTIME_PM_OPS(dw_mci_runtime_suspend,
 			   dw_mci_exynos_runtime_resume,
 			   NULL)
-	.resume_noirq = dw_mci_exynos_resume_noirq,
-	.thaw_noirq = dw_mci_exynos_resume_noirq,
-	.restore_noirq = dw_mci_exynos_resume_noirq,
 };
 
 static struct platform_driver dw_mci_exynos_pltfm_driver = {