From: Jarkko Lavinen <[EMAIL PROTECTED]>

The cover waitqueue is occasionally scheduled twice from timer
and the interrupt and oops follows. It would have been possible
to fix this problem with spinlocks but using tasklet was a dropin
sloution with no need for locking.

This path also adds some cleanups.

Signed-off-by: Jarkko Lavinen <[EMAIL PROTECTED]>
Signed-off-by: Hiroshi DOYU <[EMAIL PROTECTED]>
---
 drivers/mmc/host/omap.c |   67 ++++++++++++++++++++++++++++-------------------
 1 files changed, 40 insertions(+), 27 deletions(-)

diff --git a/drivers/mmc/host/omap.c b/drivers/mmc/host/omap.c
index 61d2293..276ccf4 100644
--- a/drivers/mmc/host/omap.c
+++ b/drivers/mmc/host/omap.c
@@ -95,7 +95,7 @@
 
 /* Specifies how often in millisecs to poll for card status changes
  * when the cover switch is open */
-#define OMAP_MMC_SWITCH_POLL_DELAY     500
+#define OMAP_MMC_COVER_POLL_DELAY      500
 
 struct mmc_omap_host;
 
@@ -107,8 +107,8 @@ struct mmc_omap_slot {
        unsigned int            fclk_freq;
        unsigned                powered:1;
 
-       struct work_struct      switch_work;
-       struct timer_list       switch_timer;
+       struct tasklet_struct   cover_tasklet;
+       struct timer_list       cover_timer;
        unsigned                cover_open;
 
        struct mmc_request      *mrq;
@@ -758,40 +758,51 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id)
        return IRQ_HANDLED;
 }
 
-void omap_mmc_notify_cover_event(struct device *dev, int slot, int is_closed)
+void omap_mmc_notify_cover_event(struct device *dev, int num, int is_closed)
 {
+       int cover_open;
        struct mmc_omap_host *host = dev_get_drvdata(dev);
+       struct mmc_omap_slot *slot = host->slots[num];
 
-       BUG_ON(slot >= host->nr_slots);
+       BUG_ON(num >= host->nr_slots);
 
        /* Other subsystems can call in here before we're initialised. */
-       if (host->nr_slots == 0 || !host->slots[slot])
+       if (host->nr_slots == 0 || !host->slots[num])
                return;
 
-       schedule_work(&host->slots[slot]->switch_work);
+       cover_open = mmc_omap_cover_is_open(slot);
+       if (cover_open != slot->cover_open) {
+               slot->cover_open = cover_open;
+               sysfs_notify(&slot->mmc->class_dev.kobj, NULL, "cover_switch");
+       }
+
+       tasklet_hi_schedule(&slot->cover_tasklet);
 }
 
-static void mmc_omap_switch_timer(unsigned long arg)
+static void mmc_omap_cover_timer(unsigned long arg)
 {
        struct mmc_omap_slot *slot = (struct mmc_omap_slot *) arg;
-
-       schedule_work(&slot->switch_work);
+       tasklet_schedule(&slot->cover_tasklet);
 }
 
-static void mmc_omap_cover_handler(struct work_struct *work)
+static void mmc_omap_cover_handler(unsigned long param)
 {
-       struct mmc_omap_slot *slot = container_of(work, struct mmc_omap_slot,
-                                                 switch_work);
-       int cover_open;
+       struct mmc_omap_slot *slot = (struct mmc_omap_slot *)param;
+       int cover_open = mmc_omap_cover_is_open(slot);
 
-       cover_open = mmc_omap_cover_is_open(slot);
-       if (cover_open != slot->cover_open) {
-               sysfs_notify(&slot->mmc->class_dev.kobj, NULL, "cover_switch");
-               slot->cover_open = cover_open;
-               dev_info(mmc_dev(slot->mmc), "cover is now %s\n",
-                        cover_open ? "open" : "closed");
-       }
-       mmc_detect_change(slot->mmc, slot->id);
+       mmc_detect_change(slot->mmc, 0);
+       if (!cover_open)
+               return;
+
+       /*
+        * If no card is inserted, we postpone polling until
+        * the cover has been closed.
+        */
+       if (slot->mmc->card == NULL || !mmc_card_present(slot->mmc->card))
+               return;
+
+       mod_timer(&slot->cover_timer,
+                 jiffies + msecs_to_jiffies(OMAP_MMC_COVER_POLL_DELAY));
 }
 
 /* Prepare to transfer the next segment of a scatterlist */
@@ -1266,10 +1277,11 @@ static int __init mmc_omap_new_slot(struct 
mmc_omap_host *host, int id)
                if (r < 0)
                        goto err_remove_slot_name;
 
-               INIT_WORK(&slot->switch_work, mmc_omap_cover_handler);
-               setup_timer(&slot->switch_timer, mmc_omap_switch_timer,
-                           (unsigned long) slot);
-               schedule_work(&slot->switch_work);
+               setup_timer(&slot->cover_timer, mmc_omap_cover_timer,
+                           (unsigned long)slot);
+               tasklet_init(&slot->cover_tasklet, mmc_omap_cover_handler,
+                            (unsigned long)slot);
+               tasklet_schedule(&slot->cover_tasklet);
        }
 
        if (slot->pdata->get_ro != NULL) {
@@ -1303,7 +1315,8 @@ static void mmc_omap_remove_slot(struct mmc_omap_slot 
*slot)
        if (slot->pdata->get_ro != NULL)
                device_remove_file(&mmc->class_dev, &dev_attr_ro);
 
-       del_timer_sync(&slot->switch_timer);
+       tasklet_kill(&slot->cover_tasklet);
+       del_timer_sync(&slot->cover_timer);
        flush_scheduled_work();
 
        mmc_remove_host(mmc);
-- 1.5.3.GIT

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