Merge tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux

Pull drm updates from Dave Airlie:
 "Core:
   - Fence destaging work
   - DRIVER_LEGACY to split off legacy drm drivers
   - drm_mm refactoring
   - Splitting drm_crtc.c into chunks and documenting better
   - Display info fixes
   - rbtree support for prime buffer lookup
   - Simple VGA DAC driver

  Panel:
   - Add Nexus 7 panel
   - More simple panels

  i915:
   - Refactoring GEM naming
   - Refactored vma/active tracking
   - Lockless request lookups
   - Better stolen memory support
   - FBC fixes
   - SKL watermark fixes
   - VGPU improvements
   - dma-buf fencing support
   - Better DP dongle support

  amdgpu:
   - Powerplay for Iceland asics
   - Improved GPU reset support
   - UVD/VEC powergating support for CZ/ST
   - Preinitialised VRAM buffer support
   - Virtual display support
   - Initial SI support
   - GTT rework
   - PCI shutdown callback support
   - HPD IRQ storm fixes

  amdkfd:
   - bugfixes

  tilcdc:
   - Atomic modesetting support

  mediatek:
   - AAL + GAMMA engine support
   - Hook up gamma LUT
   - Temporal dithering support

  imx:
   - Pixel clock from devicetree
   - drm bridge support for LVDS bridges
   - active plane reconfiguration
   - VDIC deinterlacer support
   - Frame synchronisation unit support
   - Color space conversion support

  analogix:
   - PSR support
   - Better panel on/off support

  rockchip:
   - rk3399 vop/crtc support
   - PSR support

  vc4:
   - Interlaced vblank timing
   - 3D rendering CPU overhead reduction
   - HDMI output fixes

  tda998x:
   - HDMI audio ASoC support

  sunxi:
   - Allwinner A33 support
   - better TCON support

  msm:
   - DT binding cleanups
   - Explicit fence-fd support

  sti:
   - remove sti415/416 support

  etnaviv:
   - MMUv2 refactoring
   - GC3000 support

  exynos:
   - Refactoring HDMI DCC/PHY
   - G2D pm regression fix
   - Page fault issues with wait for vblank

  There is no nouveau work in this tree, as Ben didn't get a pull
  request in, and he was fighting moving to atomic and adding mst
  support, so maybe best it waits for a cycle"

* tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux: (1412 commits)
  drm/crtc: constify drm_crtc_index parameter
  drm/i915: Fix conflict resolution from backmerge of v4.8-rc8 to drm-next
  drm/i915/guc: Unwind GuC workqueue reservation if request construction fails
  drm/i915: Reset the breadcrumbs IRQ more carefully
  drm/i915: Force relocations via cpu if we run out of idle aperture
  drm/i915: Distinguish last emitted request from last submitted request
  drm/i915: Allow DP to work w/o EDID
  drm/i915: Move long hpd handling into the hotplug work
  drm/i915/execlists: Reinitialise context image after GPU hang
  drm/i915: Use correct index for backtracking HUNG semaphores
  drm/i915: Unalias obj->phys_handle and obj->userptr
  drm/i915: Just clear the mmiodebug before a register access
  drm/i915/gen9: only add the planes actually affected by ddb changes
  drm/i915: Allow PCH DPLL sharing regardless of DPLL_SDVO_HIGH_SPEED
  drm/i915/bxt: Fix HDMI DPLL configuration
  drm/i915/gen9: fix the watermark res_blocks value
  drm/i915/gen9: fix plane_blocks_per_line on watermarks calculations
  drm/i915/gen9: minimum scanlines for Y tile is not always 4
  drm/i915/gen9: fix the WaWmMemoryReadLatency implementation
  drm/i915/kbl: KBL also needs to run the SAGV code
  ...

1 files changed, 45 insertions, 16 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 77f357b2c386..b969a64a1514 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -482,7 +482,7 @@ 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 +491,7 @@ 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 +557,7 @@ 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 +592,7 @@ 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 +713,10 @@ 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:
  *
@@ -1008,6 +1008,31 @@ 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 +1055,11 @@ 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)
@@ -1295,7 +1323,7 @@ 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);
@@ -1519,7 +1547,7 @@ 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;
@@ -1585,7 +1613,7 @@ 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 +1721,7 @@ 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 +1736,7 @@ 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 +1763,7 @@ 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 +1854,7 @@ 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);