Linux-2.6.33.2/drivers/gpu/drm/drm_irq.c
/**
* \file drm_irq.c
* IRQ support
*
* \author Rickard E. (Rik) Faith <faith@valinux.com>
* \author Gareth Hughes <gareth@valinux.com>
*/
/*
* Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
*
* Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include "drmP.h"
#include <linux/interrupt.h> /* For task queue support */
#include <linux/vgaarb.h>
/**
* Get interrupt from bus id.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_irq_busid structure.
* \return zero on success or a negative number on failure.
*
* Finds the PCI device with the specified bus id and gets its IRQ number.
* This IOCTL is deprecated, and will now return EINVAL for any busid not equal
* to that of the device that this DRM instance attached to.
*/
int drm_irq_by_busid(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_irq_busid *p = data;
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return -EINVAL;
if ((p->busnum >> 8) != drm_get_pci_domain(dev) ||
(p->busnum & 0xff) != dev->pdev->bus->number ||
p->devnum != PCI_SLOT(dev->pdev->devfn) || p->funcnum != PCI_FUNC(dev->pdev->devfn))
return -EINVAL;
p->irq = dev->pdev->irq;
DRM_DEBUG("%d:%d:%d => IRQ %d\n", p->busnum, p->devnum, p->funcnum,
p->irq);
return 0;
}
static void vblank_disable_fn(unsigned long arg)
{
struct drm_device *dev = (struct drm_device *)arg;
unsigned long irqflags;
int i;
if (!dev->vblank_disable_allowed)
return;
for (i = 0; i < dev->num_crtcs; i++) {
spin_lock_irqsave(&dev->vbl_lock, irqflags);
if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
dev->vblank_enabled[i]) {
DRM_DEBUG("disabling vblank on crtc %d\n", i);
dev->last_vblank[i] =
dev->driver->get_vblank_counter(dev, i);
dev->driver->disable_vblank(dev, i);
dev->vblank_enabled[i] = 0;
}
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
}
}
void drm_vblank_cleanup(struct drm_device *dev)
{
/* Bail if the driver didn't call drm_vblank_init() */
if (dev->num_crtcs == 0)
return;
del_timer(&dev->vblank_disable_timer);
vblank_disable_fn((unsigned long)dev);
kfree(dev->vbl_queue);
kfree(dev->_vblank_count);
kfree(dev->vblank_refcount);
kfree(dev->vblank_enabled);
kfree(dev->last_vblank);
kfree(dev->last_vblank_wait);
kfree(dev->vblank_inmodeset);
dev->num_crtcs = 0;
}
EXPORT_SYMBOL(drm_vblank_cleanup);
int drm_vblank_init(struct drm_device *dev, int num_crtcs)
{
int i, ret = -ENOMEM;
setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
(unsigned long)dev);
spin_lock_init(&dev->vbl_lock);
dev->num_crtcs = num_crtcs;
dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs,
GFP_KERNEL);
if (!dev->vbl_queue)
goto err;
dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs, GFP_KERNEL);
if (!dev->_vblank_count)
goto err;
dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs,
GFP_KERNEL);
if (!dev->vblank_refcount)
goto err;
dev->vblank_enabled = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
if (!dev->vblank_enabled)
goto err;
dev->last_vblank = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
if (!dev->last_vblank)
goto err;
dev->last_vblank_wait = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
if (!dev->last_vblank_wait)
goto err;
dev->vblank_inmodeset = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
if (!dev->vblank_inmodeset)
goto err;
/* Zero per-crtc vblank stuff */
for (i = 0; i < num_crtcs; i++) {
init_waitqueue_head(&dev->vbl_queue[i]);
atomic_set(&dev->_vblank_count[i], 0);
atomic_set(&dev->vblank_refcount[i], 0);
}
dev->vblank_disable_allowed = 0;
return 0;
err:
drm_vblank_cleanup(dev);
return ret;
}
EXPORT_SYMBOL(drm_vblank_init);
static void drm_irq_vgaarb_nokms(void *cookie, bool state)
{
struct drm_device *dev = cookie;
if (dev->driver->vgaarb_irq) {
dev->driver->vgaarb_irq(dev, state);
return;
}
if (!dev->irq_enabled)
return;
if (state)
dev->driver->irq_uninstall(dev);
else {
dev->driver->irq_preinstall(dev);
dev->driver->irq_postinstall(dev);
}
}
/**
* Install IRQ handler.
*
* \param dev DRM device.
*
* Initializes the IRQ related data. Installs the handler, calling the driver
* \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
* before and after the installation.
*/
int drm_irq_install(struct drm_device *dev)
{
int ret = 0;
unsigned long sh_flags = 0;
char *irqname;
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return -EINVAL;
if (dev->pdev->irq == 0)
return -EINVAL;
mutex_lock(&dev->struct_mutex);
/* Driver must have been initialized */
if (!dev->dev_private) {
mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}
if (dev->irq_enabled) {
mutex_unlock(&dev->struct_mutex);
return -EBUSY;
}
dev->irq_enabled = 1;
mutex_unlock(&dev->struct_mutex);
DRM_DEBUG("irq=%d\n", dev->pdev->irq);
/* Before installing handler */
dev->driver->irq_preinstall(dev);
/* Install handler */
if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
sh_flags = IRQF_SHARED;
if (dev->devname)
irqname = dev->devname;
else
irqname = dev->driver->name;
ret = request_irq(drm_dev_to_irq(dev), dev->driver->irq_handler,
sh_flags, irqname, dev);
if (ret < 0) {
mutex_lock(&dev->struct_mutex);
dev->irq_enabled = 0;
mutex_unlock(&dev->struct_mutex);
return ret;
}
if (!drm_core_check_feature(dev, DRIVER_MODESET))
vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
/* After installing handler */
ret = dev->driver->irq_postinstall(dev);
if (ret < 0) {
mutex_lock(&dev->struct_mutex);
dev->irq_enabled = 0;
mutex_unlock(&dev->struct_mutex);
}
return ret;
}
EXPORT_SYMBOL(drm_irq_install);
/**
* Uninstall the IRQ handler.
*
* \param dev DRM device.
*
* Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
*/
int drm_irq_uninstall(struct drm_device * dev)
{
unsigned long irqflags;
int irq_enabled, i;
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return -EINVAL;
mutex_lock(&dev->struct_mutex);
irq_enabled = dev->irq_enabled;
dev->irq_enabled = 0;
mutex_unlock(&dev->struct_mutex);
/*
* Wake up any waiters so they don't hang.
*/
spin_lock_irqsave(&dev->vbl_lock, irqflags);
for (i = 0; i < dev->num_crtcs; i++) {
DRM_WAKEUP(&dev->vbl_queue[i]);
dev->vblank_enabled[i] = 0;
dev->last_vblank[i] = dev->driver->get_vblank_counter(dev, i);
}
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
if (!irq_enabled)
return -EINVAL;
DRM_DEBUG("irq=%d\n", dev->pdev->irq);
if (!drm_core_check_feature(dev, DRIVER_MODESET))
vga_client_register(dev->pdev, NULL, NULL, NULL);
dev->driver->irq_uninstall(dev);
free_irq(dev->pdev->irq, dev);
return 0;
}
EXPORT_SYMBOL(drm_irq_uninstall);
/**
* IRQ control ioctl.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_control structure.
* \return zero on success or a negative number on failure.
*
* Calls irq_install() or irq_uninstall() according to \p arg.
*/
int drm_control(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_control *ctl = data;
/* if we haven't irq we fallback for compatibility reasons - this used to be a separate function in drm_dma.h */
switch (ctl->func) {
case DRM_INST_HANDLER:
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return 0;
if (drm_core_check_feature(dev, DRIVER_MODESET))
return 0;
if (dev->if_version < DRM_IF_VERSION(1, 2) &&
ctl->irq != dev->pdev->irq)
return -EINVAL;
return drm_irq_install(dev);
case DRM_UNINST_HANDLER:
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return 0;
if (drm_core_check_feature(dev, DRIVER_MODESET))
return 0;
return drm_irq_uninstall(dev);
default:
return -EINVAL;
}
}
/**
* drm_vblank_count - retrieve "cooked" vblank counter value
* @dev: DRM device
* @crtc: which counter to retrieve
*
* Fetches the "cooked" vblank count value that represents the number of
* vblank events since the system was booted, including lost events due to
* modesetting activity.
*/
u32 drm_vblank_count(struct drm_device *dev, int crtc)
{
return atomic_read(&dev->_vblank_count[crtc]);
}
EXPORT_SYMBOL(drm_vblank_count);
/**
* drm_update_vblank_count - update the master vblank counter
* @dev: DRM device
* @crtc: counter to update
*
* Call back into the driver to update the appropriate vblank counter
* (specified by @crtc). Deal with wraparound, if it occurred, and
* update the last read value so we can deal with wraparound on the next
* call if necessary.
*
* Only necessary when going from off->on, to account for frames we
* didn't get an interrupt for.
*
* Note: caller must hold dev->vbl_lock since this reads & writes
* device vblank fields.
*/
static void drm_update_vblank_count(struct drm_device *dev, int crtc)
{
u32 cur_vblank, diff;
/*
* Interrupts were disabled prior to this call, so deal with counter
* wrap if needed.
* NOTE! It's possible we lost a full dev->max_vblank_count events
* here if the register is small or we had vblank interrupts off for
* a long time.
*/
cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
diff = cur_vblank - dev->last_vblank[crtc];
if (cur_vblank < dev->last_vblank[crtc]) {
diff += dev->max_vblank_count;
DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
crtc, dev->last_vblank[crtc], cur_vblank, diff);
}
DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
crtc, diff);
atomic_add(diff, &dev->_vblank_count[crtc]);
}
/**
* drm_vblank_get - get a reference count on vblank events
* @dev: DRM device
* @crtc: which CRTC to own
*
* Acquire a reference count on vblank events to avoid having them disabled
* while in use.
*
* RETURNS
* Zero on success, nonzero on failure.
*/
int drm_vblank_get(struct drm_device *dev, int crtc)
{
unsigned long irqflags;
int ret = 0;
spin_lock_irqsave(&dev->vbl_lock, irqflags);
/* Going from 0->1 means we have to enable interrupts again */
if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
if (!dev->vblank_enabled[crtc]) {
ret = dev->driver->enable_vblank(dev, crtc);
DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret);
if (ret)
atomic_dec(&dev->vblank_refcount[crtc]);
else {
dev->vblank_enabled[crtc] = 1;
drm_update_vblank_count(dev, crtc);
}
}
} else {
if (!dev->vblank_enabled[crtc]) {
atomic_dec(&dev->vblank_refcount[crtc]);
ret = -EINVAL;
}
}
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
return ret;
}
EXPORT_SYMBOL(drm_vblank_get);
/**
* drm_vblank_put - give up ownership of vblank events
* @dev: DRM device
* @crtc: which counter to give up
*
* Release ownership of a given vblank counter, turning off interrupts
* if possible.
*/
void drm_vblank_put(struct drm_device *dev, int crtc)
{
BUG_ON (atomic_read (&dev->vblank_refcount[crtc]) == 0);
/* Last user schedules interrupt disable */
if (atomic_dec_and_test(&dev->vblank_refcount[crtc]))
mod_timer(&dev->vblank_disable_timer, jiffies + 5*DRM_HZ);
}
EXPORT_SYMBOL(drm_vblank_put);
void drm_vblank_off(struct drm_device *dev, int crtc)
{
unsigned long irqflags;
spin_lock_irqsave(&dev->vbl_lock, irqflags);
DRM_WAKEUP(&dev->vbl_queue[crtc]);
dev->vblank_enabled[crtc] = 0;
dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
}
EXPORT_SYMBOL(drm_vblank_off);
/**
* drm_vblank_pre_modeset - account for vblanks across mode sets
* @dev: DRM device
* @crtc: CRTC in question
* @post: post or pre mode set?
*
* Account for vblank events across mode setting events, which will likely
* reset the hardware frame counter.
*/
void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
{
/* vblank is not initialized (IRQ not installed ?) */
if (!dev->num_crtcs)
return;
/*
* To avoid all the problems that might happen if interrupts
* were enabled/disabled around or between these calls, we just
* have the kernel take a reference on the CRTC (just once though
* to avoid corrupting the count if multiple, mismatch calls occur),
* so that interrupts remain enabled in the interim.
*/
if (!dev->vblank_inmodeset[crtc]) {
dev->vblank_inmodeset[crtc] = 0x1;
if (drm_vblank_get(dev, crtc) == 0)
dev->vblank_inmodeset[crtc] |= 0x2;
}
}
EXPORT_SYMBOL(drm_vblank_pre_modeset);
void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
{
unsigned long irqflags;
if (dev->vblank_inmodeset[crtc]) {
spin_lock_irqsave(&dev->vbl_lock, irqflags);
dev->vblank_disable_allowed = 1;
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
if (dev->vblank_inmodeset[crtc] & 0x2)
drm_vblank_put(dev, crtc);
dev->vblank_inmodeset[crtc] = 0;
}
}
EXPORT_SYMBOL(drm_vblank_post_modeset);
/**
* drm_modeset_ctl - handle vblank event counter changes across mode switch
* @DRM_IOCTL_ARGS: standard ioctl arguments
*
* Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
* ioctls around modesetting so that any lost vblank events are accounted for.
*
* Generally the counter will reset across mode sets. If interrupts are
* enabled around this call, we don't have to do anything since the counter
* will have already been incremented.
*/
int drm_modeset_ctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_modeset_ctl *modeset = data;
int crtc, ret = 0;
/* If drm_vblank_init() hasn't been called yet, just no-op */
if (!dev->num_crtcs)
goto out;
crtc = modeset->crtc;
if (crtc >= dev->num_crtcs) {
ret = -EINVAL;
goto out;
}
switch (modeset->cmd) {
case _DRM_PRE_MODESET:
drm_vblank_pre_modeset(dev, crtc);
break;
case _DRM_POST_MODESET:
drm_vblank_post_modeset(dev, crtc);
break;
default:
ret = -EINVAL;
break;
}
out:
return ret;
}
static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
union drm_wait_vblank *vblwait,
struct drm_file *file_priv)
{
struct drm_pending_vblank_event *e;
struct timeval now;
unsigned long flags;
unsigned int seq;
e = kzalloc(sizeof *e, GFP_KERNEL);
if (e == NULL)
return -ENOMEM;
e->pipe = pipe;
e->event.base.type = DRM_EVENT_VBLANK;
e->event.base.length = sizeof e->event;
e->event.user_data = vblwait->request.signal;
e->base.event = &e->event.base;
e->base.file_priv = file_priv;
e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
do_gettimeofday(&now);
spin_lock_irqsave(&dev->event_lock, flags);
if (file_priv->event_space < sizeof e->event) {
spin_unlock_irqrestore(&dev->event_lock, flags);
kfree(e);
return -ENOMEM;
}
file_priv->event_space -= sizeof e->event;
seq = drm_vblank_count(dev, pipe);
if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
(seq - vblwait->request.sequence) <= (1 << 23)) {
vblwait->request.sequence = seq + 1;
vblwait->reply.sequence = vblwait->request.sequence;
}
DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
vblwait->request.sequence, seq, pipe);
e->event.sequence = vblwait->request.sequence;
if ((seq - vblwait->request.sequence) <= (1 << 23)) {
e->event.tv_sec = now.tv_sec;
e->event.tv_usec = now.tv_usec;
drm_vblank_put(dev, e->pipe);
list_add_tail(&e->base.link, &e->base.file_priv->event_list);
wake_up_interruptible(&e->base.file_priv->event_wait);
} else {
list_add_tail(&e->base.link, &dev->vblank_event_list);
}
spin_unlock_irqrestore(&dev->event_lock, flags);
return 0;
}
/**
* Wait for VBLANK.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param data user argument, pointing to a drm_wait_vblank structure.
* \return zero on success or a negative number on failure.
*
* This function enables the vblank interrupt on the pipe requested, then
* sleeps waiting for the requested sequence number to occur, and drops
* the vblank interrupt refcount afterwards. (vblank irq disable follows that
* after a timeout with no further vblank waits scheduled).
*/
int drm_wait_vblank(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
union drm_wait_vblank *vblwait = data;
int ret = 0;
unsigned int flags, seq, crtc;
if ((!dev->pdev->irq) || (!dev->irq_enabled))
return -EINVAL;
if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
return -EINVAL;
if (vblwait->request.type &
~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK)) {
DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
vblwait->request.type,
(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK));
return -EINVAL;
}
flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
if (crtc >= dev->num_crtcs)
return -EINVAL;
ret = drm_vblank_get(dev, crtc);
if (ret) {
DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
return ret;
}
seq = drm_vblank_count(dev, crtc);
switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
case _DRM_VBLANK_RELATIVE:
vblwait->request.sequence += seq;
vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
case _DRM_VBLANK_ABSOLUTE:
break;
default:
ret = -EINVAL;
goto done;
}
if (flags & _DRM_VBLANK_EVENT)
return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
if ((flags & _DRM_VBLANK_NEXTONMISS) &&
(seq - vblwait->request.sequence) <= (1<<23)) {
vblwait->request.sequence = seq + 1;
}
DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
vblwait->request.sequence, crtc);
dev->last_vblank_wait[crtc] = vblwait->request.sequence;
DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
(((drm_vblank_count(dev, crtc) -
vblwait->request.sequence) <= (1 << 23)) ||
!dev->irq_enabled));
if (ret != -EINTR) {
struct timeval now;
do_gettimeofday(&now);
vblwait->reply.tval_sec = now.tv_sec;
vblwait->reply.tval_usec = now.tv_usec;
vblwait->reply.sequence = drm_vblank_count(dev, crtc);
DRM_DEBUG("returning %d to client\n",
vblwait->reply.sequence);
} else {
DRM_DEBUG("vblank wait interrupted by signal\n");
}
done:
drm_vblank_put(dev, crtc);
return ret;
}
void drm_handle_vblank_events(struct drm_device *dev, int crtc)
{
struct drm_pending_vblank_event *e, *t;
struct timeval now;
unsigned long flags;
unsigned int seq;
do_gettimeofday(&now);
seq = drm_vblank_count(dev, crtc);
spin_lock_irqsave(&dev->event_lock, flags);
list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
if (e->pipe != crtc)
continue;
if ((seq - e->event.sequence) > (1<<23))
continue;
DRM_DEBUG("vblank event on %d, current %d\n",
e->event.sequence, seq);
e->event.sequence = seq;
e->event.tv_sec = now.tv_sec;
e->event.tv_usec = now.tv_usec;
drm_vblank_put(dev, e->pipe);
list_move_tail(&e->base.link, &e->base.file_priv->event_list);
wake_up_interruptible(&e->base.file_priv->event_wait);
}
spin_unlock_irqrestore(&dev->event_lock, flags);
}
/**
* drm_handle_vblank - handle a vblank event
* @dev: DRM device
* @crtc: where this event occurred
*
* Drivers should call this routine in their vblank interrupt handlers to
* update the vblank counter and send any signals that may be pending.
*/
void drm_handle_vblank(struct drm_device *dev, int crtc)
{
if (!dev->num_crtcs)
return;
atomic_inc(&dev->_vblank_count[crtc]);
DRM_WAKEUP(&dev->vbl_queue[crtc]);
drm_handle_vblank_events(dev, crtc);
}
EXPORT_SYMBOL(drm_handle_vblank);