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MMC: OMAP: Use tasklet instead of workqueue for cover switch notification

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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>
This commit is contained in:
Jarkko Lavinen 2008-03-26 16:09:42 -04:00 committed by Pierre Ossman
parent 8348f0029d
commit 7584d276d4
1 changed files with 44 additions and 31 deletions
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75
drivers/mmc/host/omap.c
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@ -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 @@ 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;
@ -740,40 +740,51 @@ 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);
}
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 @@ 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);
}
return 0;
@ -1263,7 +1275,8 @@ static void mmc_omap_remove_slot(struct mmc_omap_slot *slot)
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);