mmc: core: Validate suspend prerequisites for SDIO at SUSPEND_PREPARE

This patch moves the validation for all the suspend prerequisites to be
done at SUSPEND_PREPARE notification. Previously in the SDIO case parts
of the validation was done from mmc_suspend_host.

This patch invents a new pre_suspend bus_ops callback and implements it
for SDIO. Returning an error code from it, will mean at SUSPEND_PREPARE
notification, the card will be removed before proceeding with the
suspend sequence.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

3 files changed, 32 insertions, 21 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index d2ee2829b313..7a8a42d3a039 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2628,22 +2628,6 @@ int mmc_suspend_host(struct mmc_host *host)
         if (host->bus_ops && !host->bus_dead) {
                 if (host->bus_ops->suspend)
                         err = host->bus_ops->suspend(host);
-
-                if (err == -ENOSYS || !host->bus_ops->resume) {
-                        /*
-                         * We simply "remove" the card in this case.
-                         * It will be redetected on resume.  (Calling
-                         * bus_ops->remove() with a claimed host can
-                         * deadlock.)
-                         */
-                        host->bus_ops->remove(host);
-                        mmc_claim_host(host);
-                        mmc_detach_bus(host);
-                        mmc_power_off(host);
-                        mmc_release_host(host);
-                        host->pm_flags = 0;
-                        err = 0;
-                }
         }
         mmc_bus_put(host);
 
@@ -2706,6 +2690,7 @@ int mmc_pm_notify(struct notifier_block *notify_block,
         struct mmc_host *host = container_of(
                 notify_block, struct mmc_host, pm_notify);
         unsigned long flags;
+        int err = 0;
 
         switch (mode) {
         case PM_HIBERNATION_PREPARE:
@@ -2715,7 +2700,13 @@ int mmc_pm_notify(struct notifier_block *notify_block,
                 spin_unlock_irqrestore(&host->lock, flags);
                 cancel_delayed_work_sync(&host->detect);
 
-                if (!host->bus_ops || host->bus_ops->suspend)
+                if (!host->bus_ops)
+                        break;
+
+                /* Validate prerequisites for suspend */
+                if (host->bus_ops->pre_suspend)
+                        err = host->bus_ops->pre_suspend(host);
+                if (!err && host->bus_ops->suspend)
                         break;
 
                 /* Calling bus_ops->remove() with a claimed host can deadlock */
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 52a3650307af..79f37cfc373b 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -18,6 +18,7 @@
 struct mmc_bus_ops {
         void (*remove)(struct mmc_host *);
         void (*detect)(struct mmc_host *);
+        int (*pre_suspend)(struct mmc_host *);
         int (*suspend)(struct mmc_host *);
         int (*resume)(struct mmc_host *);
         int (*runtime_suspend)(struct mmc_host *);
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 1fbbd1bc55ec..be8cca8d3024 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -910,11 +910,11 @@ out:
 }
 
 /*
- * SDIO suspend.  We need to suspend all functions separately.
+ * SDIO pre_suspend.  We need to suspend all functions separately.
  * Therefore all registered functions must have drivers with suspend
  * and resume methods.  Failing that we simply remove the whole card.
  */
-static int mmc_sdio_suspend(struct mmc_host *host)
+static int mmc_sdio_pre_suspend(struct mmc_host *host)
 {
         int i, err = 0;
 
@@ -925,8 +925,26 @@ static int mmc_sdio_suspend(struct mmc_host *host)
                         if (!pmops || !pmops->suspend || !pmops->resume) {
                                 /* force removal of entire card in that case */
                                 err = -ENOSYS;
-                        } else
-                                err = pmops->suspend(&func->dev);
+                                break;
+                        }
+                }
+        }
+
+        return err;
+}
+
+/*
+ * SDIO suspend.  Suspend all functions separately.
+ */
+static int mmc_sdio_suspend(struct mmc_host *host)
+{
+        int i, err = 0;
+
+        for (i = 0; i < host->card->sdio_funcs; i++) {
+                struct sdio_func *func = host->card->sdio_func[i];
+                if (func && sdio_func_present(func) && func->dev.driver) {
+                        const struct dev_pm_ops *pmops = func->dev.driver->pm;
+                        err = pmops->suspend(&func->dev);
                         if (err)
                                 break;
                 }
@@ -1076,6 +1094,7 @@ static int mmc_sdio_runtime_resume(struct mmc_host *host)
 static const struct mmc_bus_ops mmc_sdio_ops = {
         .remove = mmc_sdio_remove,
         .detect = mmc_sdio_detect,
+        .pre_suspend = mmc_sdio_pre_suspend,
         .suspend = mmc_sdio_suspend,
         .resume = mmc_sdio_resume,
         .runtime_suspend = mmc_sdio_runtime_suspend,