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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2017-01-24 09:57:18 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2017-01-24 09:57:18 -0800
commit62ed8ceda1699acae01b666497f004bfd3d67a6f (patch)
treefe38c83c49dfd568b540666948ef78cb9d082c38 /drivers/gpu/drm/drm_irq.c
parent1c3415a06b1016a596bfe59e0cfee56c773aa958 (diff)
parent7a308bb3016f57e5be11a677d15b821536419d36 (diff)
Merge tag 'v4.10-rc5' into for-linus
Sync up with mainline to apply fixup to a commit that came through power supply tree.
Diffstat (limited to 'drivers/gpu/drm/drm_irq.c')
-rw-r--r--drivers/gpu/drm/drm_irq.c225
1 files changed, 85 insertions, 140 deletions
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 77f357b2c386..273625a85036 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -93,7 +93,7 @@ static void store_vblank(struct drm_device *dev, unsigned int pipe,
* Reset the stored timestamp for the current vblank count to correspond
* to the last vblank occurred.
*
- * Only to be called from drm_vblank_on().
+ * Only to be called from drm_crtc_vblank_on().
*
* Note: caller must hold dev->vbl_lock since this reads & writes
* device vblank fields.
@@ -234,6 +234,16 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
store_vblank(dev, pipe, diff, &t_vblank, cur_vblank);
}
+static u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+
+ if (WARN_ON(pipe >= dev->num_crtcs))
+ return 0;
+
+ return vblank->count;
+}
+
/**
* drm_accurate_vblank_count - retrieve the master vblank counter
* @crtc: which counter to retrieve
@@ -296,7 +306,7 @@ static void vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
* Always update the count and timestamp to maintain the
* appearance that the counter has been ticking all along until
* this time. This makes the count account for the entire time
- * between drm_vblank_on() and drm_vblank_off().
+ * between drm_crtc_vblank_on() and drm_crtc_vblank_off().
*/
drm_update_vblank_count(dev, pipe, 0);
@@ -482,7 +492,7 @@ int drm_irq_install(struct drm_device *dev, int irq)
return ret;
}
- if (!drm_core_check_feature(dev, DRIVER_MODESET))
+ if (drm_core_check_feature(dev, DRIVER_LEGACY))
vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
/* After installing handler */
@@ -491,7 +501,7 @@ int drm_irq_install(struct drm_device *dev, int irq)
if (ret < 0) {
dev->irq_enabled = false;
- if (!drm_core_check_feature(dev, DRIVER_MODESET))
+ if (drm_core_check_feature(dev, DRIVER_LEGACY))
vga_client_register(dev->pdev, NULL, NULL, NULL);
free_irq(irq, dev);
} else {
@@ -557,7 +567,7 @@ int drm_irq_uninstall(struct drm_device *dev)
DRM_DEBUG("irq=%d\n", dev->irq);
- if (!drm_core_check_feature(dev, DRIVER_MODESET))
+ if (drm_core_check_feature(dev, DRIVER_LEGACY))
vga_client_register(dev->pdev, NULL, NULL, NULL);
if (dev->driver->irq_uninstall)
@@ -592,7 +602,7 @@ int drm_control(struct drm_device *dev, void *data,
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return 0;
- if (drm_core_check_feature(dev, DRIVER_MODESET))
+ if (!drm_core_check_feature(dev, DRIVER_LEGACY))
return 0;
/* UMS was only ever supported on pci devices. */
if (WARN_ON(!dev->pdev))
@@ -713,10 +723,10 @@ EXPORT_SYMBOL(drm_calc_timestamping_constants);
* Negative value on error, failure or if not supported in current
* video mode:
*
- * -EINVAL - Invalid CRTC.
- * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
- * -ENOTSUPP - Function not supported in current display mode.
- * -EIO - Failed, e.g., due to failed scanout position query.
+ * -EINVAL Invalid CRTC.
+ * -EAGAIN Temporary unavailable, e.g., called before initial modeset.
+ * -ENOTSUPP Function not supported in current display mode.
+ * -EIO Failed, e.g., due to failed scanout position query.
*
* Returns or'ed positive status flags on success:
*
@@ -888,31 +898,6 @@ drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
}
/**
- * drm_vblank_count - retrieve "cooked" vblank counter value
- * @dev: DRM device
- * @pipe: index of CRTC for which to retrieve the counter
- *
- * 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.
- *
- * This is the legacy version of drm_crtc_vblank_count().
- *
- * Returns:
- * The software vblank counter.
- */
-u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
-{
- struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
-
- if (WARN_ON(pipe >= dev->num_crtcs))
- return 0;
-
- return vblank->count;
-}
-EXPORT_SYMBOL(drm_vblank_count);
-
-/**
* drm_crtc_vblank_count - retrieve "cooked" vblank counter value
* @crtc: which counter to retrieve
*
@@ -920,8 +905,6 @@ EXPORT_SYMBOL(drm_vblank_count);
* vblank events since the system was booted, including lost events due to
* modesetting activity.
*
- * This is the native KMS version of drm_vblank_count().
- *
* Returns:
* The software vblank counter.
*/
@@ -952,8 +935,10 @@ static u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
u32 vblank_count;
unsigned int seq;
- if (WARN_ON(pipe >= dev->num_crtcs))
+ if (WARN_ON(pipe >= dev->num_crtcs)) {
+ *vblanktime = (struct timeval) { 0 };
return 0;
+ }
do {
seq = read_seqbegin(&vblank->seqlock);
@@ -1008,6 +993,31 @@ static void send_vblank_event(struct drm_device *dev,
* period. This helper function implements exactly the required vblank arming
* behaviour.
*
+ * NOTE: Drivers using this to send out the event in struct &drm_crtc_state
+ * as part of an atomic commit must ensure that the next vblank happens at
+ * exactly the same time as the atomic commit is committed to the hardware. This
+ * function itself does **not** protect again the next vblank interrupt racing
+ * with either this function call or the atomic commit operation. A possible
+ * sequence could be:
+ *
+ * 1. Driver commits new hardware state into vblank-synchronized registers.
+ * 2. A vblank happens, committing the hardware state. Also the corresponding
+ * vblank interrupt is fired off and fully processed by the interrupt
+ * handler.
+ * 3. The atomic commit operation proceeds to call drm_crtc_arm_vblank_event().
+ * 4. The event is only send out for the next vblank, which is wrong.
+ *
+ * An equivalent race can happen when the driver calls
+ * drm_crtc_arm_vblank_event() before writing out the new hardware state.
+ *
+ * The only way to make this work safely is to prevent the vblank from firing
+ * (and the hardware from committing anything else) until the entire atomic
+ * commit sequence has run to completion. If the hardware does not have such a
+ * feature (e.g. using a "go" bit), then it is unsafe to use this functions.
+ * Instead drivers need to manually send out the event from their interrupt
+ * handler by calling drm_crtc_send_vblank_event() and make sure that there's no
+ * possible race with the hardware committing the atomic update.
+ *
* Caller must hold event lock. Caller must also hold a vblank reference for
* the event @e, which will be dropped when the next vblank arrives.
*/
@@ -1030,8 +1040,11 @@ EXPORT_SYMBOL(drm_crtc_arm_vblank_event);
* @crtc: the source CRTC of the vblank event
* @e: the event to send
*
- * Updates sequence # and timestamp on event, and sends it to userspace.
- * Caller must hold event lock.
+ * Updates sequence # and timestamp on event for the most recently processed
+ * vblank, and sends it to userspace. Caller must hold event lock.
+ *
+ * See drm_crtc_arm_vblank_event() for a helper which can be used in certain
+ * situation, especially to send out events for atomic commit operations.
*/
void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
struct drm_pending_vblank_event *e)
@@ -1242,21 +1255,20 @@ void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
/**
- * drm_vblank_off - disable vblank events on a CRTC
- * @dev: DRM device
- * @pipe: CRTC index
+ * drm_crtc_vblank_off - disable vblank events on a CRTC
+ * @crtc: CRTC in question
*
* Drivers can use this function to shut down the vblank interrupt handling when
* disabling a crtc. This function ensures that the latest vblank frame count is
- * stored so that drm_vblank_on() can restore it again.
+ * stored so that drm_vblank_on can restore it again.
*
* Drivers must use this function when the hardware vblank counter can get
* reset, e.g. when suspending.
- *
- * This is the legacy version of drm_crtc_vblank_off().
*/
-void drm_vblank_off(struct drm_device *dev, unsigned int pipe)
+void drm_crtc_vblank_off(struct drm_crtc *crtc)
{
+ struct drm_device *dev = crtc->dev;
+ unsigned int pipe = drm_crtc_index(crtc);
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
struct drm_pending_vblank_event *e, *t;
struct timeval now;
@@ -1272,7 +1284,8 @@ void drm_vblank_off(struct drm_device *dev, unsigned int pipe)
DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
pipe, vblank->enabled, vblank->inmodeset);
- /* Avoid redundant vblank disables without previous drm_vblank_on(). */
+ /* Avoid redundant vblank disables without previous
+ * drm_crtc_vblank_on(). */
if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset)
vblank_disable_and_save(dev, pipe);
@@ -1295,7 +1308,7 @@ void drm_vblank_off(struct drm_device *dev, unsigned int pipe)
if (e->pipe != pipe)
continue;
DRM_DEBUG("Sending premature vblank event on disable: "
- "wanted %d, current %d\n",
+ "wanted %u, current %u\n",
e->event.sequence, seq);
list_del(&e->base.link);
drm_vblank_put(dev, pipe);
@@ -1303,25 +1316,6 @@ void drm_vblank_off(struct drm_device *dev, unsigned int pipe)
}
spin_unlock_irqrestore(&dev->event_lock, irqflags);
}
-EXPORT_SYMBOL(drm_vblank_off);
-
-/**
- * drm_crtc_vblank_off - disable vblank events on a CRTC
- * @crtc: CRTC in question
- *
- * Drivers can use this function to shut down the vblank interrupt handling when
- * disabling a crtc. This function ensures that the latest vblank frame count is
- * stored so that drm_vblank_on can restore it again.
- *
- * Drivers must use this function when the hardware vblank counter can get
- * reset, e.g. when suspending.
- *
- * This is the native kms version of drm_vblank_off().
- */
-void drm_crtc_vblank_off(struct drm_crtc *crtc)
-{
- drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
-}
EXPORT_SYMBOL(drm_crtc_vblank_off);
/**
@@ -1357,19 +1351,18 @@ void drm_crtc_vblank_reset(struct drm_crtc *crtc)
EXPORT_SYMBOL(drm_crtc_vblank_reset);
/**
- * drm_vblank_on - enable vblank events on a CRTC
- * @dev: DRM device
- * @pipe: CRTC index
+ * drm_crtc_vblank_on - enable vblank events on a CRTC
+ * @crtc: CRTC in question
*
* This functions restores the vblank interrupt state captured with
- * drm_vblank_off() again. Note that calls to drm_vblank_on() and
- * drm_vblank_off() can be unbalanced and so can also be unconditionally called
+ * drm_crtc_vblank_off() again. Note that calls to drm_crtc_vblank_on() and
+ * drm_crtc_vblank_off() can be unbalanced and so can also be unconditionally called
* in driver load code to reflect the current hardware state of the crtc.
- *
- * This is the legacy version of drm_crtc_vblank_on().
*/
-void drm_vblank_on(struct drm_device *dev, unsigned int pipe)
+void drm_crtc_vblank_on(struct drm_crtc *crtc)
{
+ struct drm_device *dev = crtc->dev;
+ unsigned int pipe = drm_crtc_index(crtc);
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
unsigned long irqflags;
@@ -1396,49 +1389,10 @@ void drm_vblank_on(struct drm_device *dev, unsigned int pipe)
WARN_ON(drm_vblank_enable(dev, pipe));
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
}
-EXPORT_SYMBOL(drm_vblank_on);
-
-/**
- * drm_crtc_vblank_on - enable vblank events on a CRTC
- * @crtc: CRTC in question
- *
- * This functions restores the vblank interrupt state captured with
- * drm_vblank_off() again. Note that calls to drm_vblank_on() and
- * drm_vblank_off() can be unbalanced and so can also be unconditionally called
- * in driver load code to reflect the current hardware state of the crtc.
- *
- * This is the native kms version of drm_vblank_on().
- */
-void drm_crtc_vblank_on(struct drm_crtc *crtc)
-{
- drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
-}
EXPORT_SYMBOL(drm_crtc_vblank_on);
-/**
- * drm_vblank_pre_modeset - account for vblanks across mode sets
- * @dev: DRM device
- * @pipe: CRTC index
- *
- * Account for vblank events across mode setting events, which will likely
- * reset the hardware frame counter.
- *
- * This is done by grabbing a temporary vblank reference to ensure that the
- * vblank interrupt keeps running across the modeset sequence. With this the
- * software-side vblank frame counting will ensure that there are no jumps or
- * discontinuities.
- *
- * Unfortunately this approach is racy and also doesn't work when the vblank
- * interrupt stops running, e.g. across system suspend resume. It is therefore
- * highly recommended that drivers use the newer drm_vblank_off() and
- * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
- * using "cooked" software vblank frame counters and not relying on any hardware
- * counters.
- *
- * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
- * again.
- */
-void drm_vblank_pre_modeset(struct drm_device *dev, unsigned int pipe)
+static void drm_legacy_vblank_pre_modeset(struct drm_device *dev,
+ unsigned int pipe)
{
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
@@ -1462,17 +1416,9 @@ void drm_vblank_pre_modeset(struct drm_device *dev, unsigned int pipe)
vblank->inmodeset |= 0x2;
}
}
-EXPORT_SYMBOL(drm_vblank_pre_modeset);
-/**
- * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
- * @dev: DRM device
- * @pipe: CRTC index
- *
- * This function again drops the temporary vblank reference acquired in
- * drm_vblank_pre_modeset.
- */
-void drm_vblank_post_modeset(struct drm_device *dev, unsigned int pipe)
+static void drm_legacy_vblank_post_modeset(struct drm_device *dev,
+ unsigned int pipe)
{
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
unsigned long irqflags;
@@ -1495,7 +1441,6 @@ void drm_vblank_post_modeset(struct drm_device *dev, unsigned int pipe)
vblank->inmodeset = 0;
}
}
-EXPORT_SYMBOL(drm_vblank_post_modeset);
/*
* drm_modeset_ctl - handle vblank event counter changes across mode switch
@@ -1519,7 +1464,7 @@ int drm_modeset_ctl(struct drm_device *dev, void *data,
return 0;
/* KMS drivers handle this internally */
- if (drm_core_check_feature(dev, DRIVER_MODESET))
+ if (!drm_core_check_feature(dev, DRIVER_LEGACY))
return 0;
pipe = modeset->crtc;
@@ -1528,10 +1473,10 @@ int drm_modeset_ctl(struct drm_device *dev, void *data,
switch (modeset->cmd) {
case _DRM_PRE_MODESET:
- drm_vblank_pre_modeset(dev, pipe);
+ drm_legacy_vblank_pre_modeset(dev, pipe);
break;
case _DRM_POST_MODESET:
- drm_vblank_post_modeset(dev, pipe);
+ drm_legacy_vblank_post_modeset(dev, pipe);
break;
default:
return -EINVAL;
@@ -1566,11 +1511,10 @@ static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
spin_lock_irqsave(&dev->event_lock, flags);
/*
- * drm_vblank_off() might have been called after we called
- * drm_vblank_get(). drm_vblank_off() holds event_lock
- * around the vblank disable, so no need for further locking.
- * The reference from drm_vblank_get() protects against
- * vblank disable from another source.
+ * drm_crtc_vblank_off() might have been called after we called
+ * drm_vblank_get(). drm_crtc_vblank_off() holds event_lock around the
+ * vblank disable, so no need for further locking. The reference from
+ * drm_vblank_get() protects against vblank disable from another source.
*/
if (!vblank->enabled) {
ret = -EINVAL;
@@ -1585,7 +1529,7 @@ static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
seq = drm_vblank_count_and_time(dev, pipe, &now);
- DRM_DEBUG("event on vblank count %d, current %d, crtc %u\n",
+ DRM_DEBUG("event on vblank count %u, current %u, crtc %u\n",
vblwait->request.sequence, seq, pipe);
trace_drm_vblank_event_queued(current->pid, pipe,
@@ -1693,7 +1637,7 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
return drm_queue_vblank_event(dev, pipe, vblwait, file_priv);
}
- DRM_DEBUG("waiting on vblank count %d, crtc %u\n",
+ DRM_DEBUG("waiting on vblank count %u, crtc %u\n",
vblwait->request.sequence, pipe);
DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
(((drm_vblank_count(dev, pipe) -
@@ -1708,7 +1652,7 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
vblwait->reply.tval_sec = now.tv_sec;
vblwait->reply.tval_usec = now.tv_usec;
- DRM_DEBUG("returning %d to client\n",
+ DRM_DEBUG("returning %u to client\n",
vblwait->reply.sequence);
} else {
DRM_DEBUG("vblank wait interrupted by signal\n");
@@ -1735,7 +1679,7 @@ static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
if ((seq - e->event.sequence) > (1<<23))
continue;
- DRM_DEBUG("vblank event on %d, current %d\n",
+ DRM_DEBUG("vblank event on %u, current %u\n",
e->event.sequence, seq);
list_del(&e->base.link);
@@ -1826,6 +1770,7 @@ EXPORT_SYMBOL(drm_crtc_handle_vblank);
*/
u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe)
{
+ WARN_ON_ONCE(dev->max_vblank_count != 0);
return 0;
}
EXPORT_SYMBOL(drm_vblank_no_hw_counter);