linux/drivers/gpu/drm/msm/mdp/mdp_kms.c
Rob Clark 30b6f8f679 drm/msm/mdp: add timeout for irq wait
Make things recover a bit more gracefully if we get stuck with no vblank
irq ever coming.

Signed-off-by: Rob Clark <robdclark@gmail.com>
2014-03-31 10:27:46 -04:00

146 lines
3.4 KiB
C

/*
* Copyright (C) 2013 Red Hat
* Author: Rob Clark <robdclark@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "msm_drv.h"
#include "mdp_kms.h"
struct mdp_irq_wait {
struct mdp_irq irq;
int count;
};
static DECLARE_WAIT_QUEUE_HEAD(wait_event);
static DEFINE_SPINLOCK(list_lock);
static void update_irq(struct mdp_kms *mdp_kms)
{
struct mdp_irq *irq;
uint32_t irqmask = mdp_kms->vblank_mask;
BUG_ON(!spin_is_locked(&list_lock));
list_for_each_entry(irq, &mdp_kms->irq_list, node)
irqmask |= irq->irqmask;
mdp_kms->funcs->set_irqmask(mdp_kms, irqmask);
}
static void update_irq_unlocked(struct mdp_kms *mdp_kms)
{
unsigned long flags;
spin_lock_irqsave(&list_lock, flags);
update_irq(mdp_kms);
spin_unlock_irqrestore(&list_lock, flags);
}
void mdp_dispatch_irqs(struct mdp_kms *mdp_kms, uint32_t status)
{
struct mdp_irq *handler, *n;
unsigned long flags;
spin_lock_irqsave(&list_lock, flags);
mdp_kms->in_irq = true;
list_for_each_entry_safe(handler, n, &mdp_kms->irq_list, node) {
if (handler->irqmask & status) {
spin_unlock_irqrestore(&list_lock, flags);
handler->irq(handler, handler->irqmask & status);
spin_lock_irqsave(&list_lock, flags);
}
}
mdp_kms->in_irq = false;
update_irq(mdp_kms);
spin_unlock_irqrestore(&list_lock, flags);
}
void mdp_update_vblank_mask(struct mdp_kms *mdp_kms, uint32_t mask, bool enable)
{
unsigned long flags;
spin_lock_irqsave(&list_lock, flags);
if (enable)
mdp_kms->vblank_mask |= mask;
else
mdp_kms->vblank_mask &= ~mask;
update_irq(mdp_kms);
spin_unlock_irqrestore(&list_lock, flags);
}
static void wait_irq(struct mdp_irq *irq, uint32_t irqstatus)
{
struct mdp_irq_wait *wait =
container_of(irq, struct mdp_irq_wait, irq);
wait->count--;
wake_up_all(&wait_event);
}
void mdp_irq_wait(struct mdp_kms *mdp_kms, uint32_t irqmask)
{
struct mdp_irq_wait wait = {
.irq = {
.irq = wait_irq,
.irqmask = irqmask,
},
.count = 1,
};
mdp_irq_register(mdp_kms, &wait.irq);
wait_event_timeout(wait_event, (wait.count <= 0),
msecs_to_jiffies(100));
mdp_irq_unregister(mdp_kms, &wait.irq);
}
void mdp_irq_register(struct mdp_kms *mdp_kms, struct mdp_irq *irq)
{
unsigned long flags;
bool needs_update = false;
spin_lock_irqsave(&list_lock, flags);
if (!irq->registered) {
irq->registered = true;
list_add(&irq->node, &mdp_kms->irq_list);
needs_update = !mdp_kms->in_irq;
}
spin_unlock_irqrestore(&list_lock, flags);
if (needs_update)
update_irq_unlocked(mdp_kms);
}
void mdp_irq_unregister(struct mdp_kms *mdp_kms, struct mdp_irq *irq)
{
unsigned long flags;
bool needs_update = false;
spin_lock_irqsave(&list_lock, flags);
if (irq->registered) {
irq->registered = false;
list_del(&irq->node);
needs_update = !mdp_kms->in_irq;
}
spin_unlock_irqrestore(&list_lock, flags);
if (needs_update)
update_irq_unlocked(mdp_kms);
}