mmc: core: Hold a wake lock accross delayed work + mmc rescan

Signed-off-by: San Mehat <san@android.com>
mmc: core: Rework mmc_delayed_work wakelock so that the wakelock is only extended if a card is added or removed.

Signed-off-by: San Mehat <san@google.com>

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index cfb8ee6..f195ce3 100644 (file)
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -23,6 +23,7 @@
 #include <linux/log2.h>
 #include <linux/regulator/consumer.h>
 #include <linux/pm_runtime.h>
+#include <linux/wakelock.h>
 
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
@@ -39,6 +40,7 @@
 #include "sdio_ops.h"
 
 static struct workqueue_struct *workqueue;
+static struct wake_lock mmc_delayed_work_wake_lock;
 
 /*
  * Enabling software CRCs on the data blocks can be a significant (30%)
@@ -71,6 +73,7 @@ MODULE_PARM_DESC(
 static int mmc_schedule_delayed_work(struct delayed_work *work,
                                     unsigned long delay)
 {
+       wake_lock(&mmc_delayed_work_wake_lock);
        return queue_delayed_work(workqueue, work, delay);
 }
 
@@ -1595,6 +1598,7 @@ void mmc_rescan(struct work_struct *work)
        struct mmc_host *host =
                container_of(work, struct mmc_host, detect.work);
        int i;
+       bool extend_wakelock = false;
 
        if (host->rescan_disable)
                return;
@@ -1633,14 +1637,20 @@ void mmc_rescan(struct work_struct *work)
 
        mmc_claim_host(host);
        for (i = 0; i < ARRAY_SIZE(freqs); i++) {
-               if (!mmc_rescan_try_freq(host, max(freqs[i], host->f_min)))
+               if (!mmc_rescan_try_freq(host, max(freqs[i], host->f_min))) {
+                       extend_wakelock = true;
                        break;
+               }
                if (freqs[i] <= host->f_min)
                        break;
        }
        mmc_release_host(host);
 
  out:
+       if (extend_wakelock)
+               wake_lock_timeout(&mmc_delayed_work_wake_lock, HZ / 2);
+       else
+               wake_unlock(&mmc_delayed_work_wake_lock);
        if (host->caps & MMC_CAP_NEEDS_POLL)
                mmc_schedule_delayed_work(&host->detect, HZ);
 }
@@ -1926,6 +1936,9 @@ static int __init mmc_init(void)
        if (!workqueue)
                return -ENOMEM;
 
+       wake_lock_init(&mmc_delayed_work_wake_lock, WAKE_LOCK_SUSPEND,
+                      "mmc_delayed_work");
+
        ret = mmc_register_bus();
        if (ret)
                goto destroy_workqueue;
@@ -1946,6 +1959,7 @@ unregister_bus:
        mmc_unregister_bus();
 destroy_workqueue:
        destroy_workqueue(workqueue);
+       wake_lock_destroy(&mmc_delayed_work_wake_lock);
 
        return ret;
 }
@@ -1956,6 +1970,7 @@ static void __exit mmc_exit(void)
        mmc_unregister_host_class();
        mmc_unregister_bus();
        destroy_workqueue(workqueue);
+       wake_lock_destroy(&mmc_delayed_work_wake_lock);
 }
 
 subsys_initcall(mmc_init);