MMC: OMAP: Use tasklet instead of workqueue for cover switch notification
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
solution with no need for locking.
This path also adds some cleanups.
Signed-off-by: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/host/omap.c b/drivers/mmc/host/omap.c
index f7fb978..8f393e8 100644
--- a/drivers/mmc/host/omap.c
+++ b/drivers/mmc/host/omap.c
@@ -94,7 +94,7 @@
/* 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;
@@ -106,8 +106,8 @@
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;
@@ -740,40 +740,51 @@
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);
-}
-
-static void mmc_omap_switch_timer(unsigned long arg)
-{
- struct mmc_omap_slot *slot = (struct mmc_omap_slot *) arg;
-
- schedule_work(&slot->switch_work);
-}
-
-static void mmc_omap_cover_handler(struct work_struct *work)
-{
- struct mmc_omap_slot *slot = container_of(work, struct mmc_omap_slot,
- switch_work);
- int cover_open;
-
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");
+ sysfs_notify(&slot->mmc->class_dev.kobj, NULL, "cover_switch");
}
- mmc_detect_change(slot->mmc, slot->id);
+
+ tasklet_hi_schedule(&slot->cover_tasklet);
+}
+
+static void mmc_omap_cover_timer(unsigned long arg)
+{
+ struct mmc_omap_slot *slot = (struct mmc_omap_slot *) arg;
+ tasklet_schedule(&slot->cover_tasklet);
+}
+
+static void mmc_omap_cover_handler(unsigned long param)
+{
+ struct mmc_omap_slot *slot = (struct mmc_omap_slot *)param;
+ int cover_open = mmc_omap_cover_is_open(slot);
+
+ 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 */
@@ -1237,10 +1248,11 @@
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);
}
return 0;
@@ -1263,7 +1275,8 @@
if (slot->pdata->get_cover_state != NULL)
device_remove_file(&mmc->class_dev, &dev_attr_cover_switch);
- del_timer_sync(&slot->switch_timer);
+ tasklet_kill(&slot->cover_tasklet);
+ del_timer_sync(&slot->cover_timer);
flush_scheduled_work();
mmc_remove_host(mmc);
