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omap: mailbox: convert rwlocks to spinlock

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rwlocks are slower and have potential starvation issues
therefore spinlocks are generally preferred.

see also: http://lwn.net/Articles/364583/

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Kanigeri Hari <h-kanigeri2@ti.com>
Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
This commit is contained in:
Ohad Ben-Cohen 2010-05-05 15:33:06 +00:00 committed by Hiroshi DOYU
parent 1ea5d6d18b
commit 10d1a0028d
1 changed files with 10 additions and 10 deletions
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20
arch/arm/plat-omap/mailbox.c
View file

@ -31,7 +31,7 @@
static struct workqueue_struct *mboxd;
static struct omap_mbox *mboxes;
static DEFINE_RWLOCK(mboxes_lock);
static DEFINE_SPINLOCK(mboxes_lock);
static bool rq_full;
static int mbox_configured;
@ -341,14 +341,14 @@ struct omap_mbox *omap_mbox_get(const char *name)
struct omap_mbox *mbox;
int ret;
read_lock(&mboxes_lock);
spin_lock(&mboxes_lock);
mbox = *(find_mboxes(name));
if (mbox == NULL) {
read_unlock(&mboxes_lock);
spin_unlock(&mboxes_lock);
return ERR_PTR(-ENOENT);
}
read_unlock(&mboxes_lock);
spin_unlock(&mboxes_lock);
ret = omap_mbox_startup(mbox);
if (ret)
@ -374,15 +374,15 @@ int omap_mbox_register(struct device *parent, struct omap_mbox *mbox)
if (mbox->next)
return -EBUSY;
write_lock(&mboxes_lock);
spin_lock(&mboxes_lock);
tmp = find_mboxes(mbox->name);
if (*tmp) {
ret = -EBUSY;
write_unlock(&mboxes_lock);
spin_unlock(&mboxes_lock);
goto err_find;
}
*tmp = mbox;
write_unlock(&mboxes_lock);
spin_unlock(&mboxes_lock);
return 0;
@ -395,18 +395,18 @@ int omap_mbox_unregister(struct omap_mbox *mbox)
{
struct omap_mbox **tmp;
write_lock(&mboxes_lock);
spin_lock(&mboxes_lock);
tmp = &mboxes;
while (*tmp) {
if (mbox == *tmp) {
*tmp = mbox->next;
mbox->next = NULL;
write_unlock(&mboxes_lock);
spin_unlock(&mboxes_lock);
return 0;
}
tmp = &(*tmp)->next;
}
write_unlock(&mboxes_lock);
spin_unlock(&mboxes_lock);
return -EINVAL;
}