Merge tag 'for-v4.6-rc/omap-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v4.6/fixes

ARM: OMAP2+: first hwmod fix for v4.6-rc

Fix a longstanding bug in the hwmod code that could cause
hardware SYSCONFIG register values to not match the kernel's
idea of what they should be, and that could result in lower
performance during IP block idle entry.

Basic build, boot, and PM test logs are available here:

http://www.pwsan.com/omap/testlogs/omap-hwmod-fixes-a-for-v4.6-rc/20160326231727/

1 files changed, 43 insertions, 30 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index acd066d0a805..f0ed974bd4e0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -35,32 +35,30 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_edid.h>
 
-static void amdgpu_flip_wait_fence(struct amdgpu_device *adev,
-				   struct fence **f)
+static void amdgpu_flip_callback(struct fence *f, struct fence_cb *cb)
 {
-	struct amdgpu_fence *fence;
-	long r;
+	struct amdgpu_flip_work *work =
+		container_of(cb, struct amdgpu_flip_work, cb);
 
-	if (*f == NULL)
-		return;
+	fence_put(f);
+	schedule_work(&work->flip_work);
+}
 
-	fence = to_amdgpu_fence(*f);
-	if (fence) {
-		r = fence_wait(&fence->base, false);
-		if (r == -EDEADLK)
-			r = amdgpu_gpu_reset(adev);
-	} else
-		r = fence_wait(*f, false);
+static bool amdgpu_flip_handle_fence(struct amdgpu_flip_work *work,
+				     struct fence **f)
+{
+	struct fence *fence= *f;
+
+	if (fence == NULL)
+		return false;
 
-	if (r)
-		DRM_ERROR("failed to wait on page flip fence (%ld)!\n", r);
+	*f = NULL;
+
+	if (!fence_add_callback(fence, &work->cb, amdgpu_flip_callback))
+		return true;
 
-	/* We continue with the page flip even if we failed to wait on
-	 * the fence, otherwise the DRM core and userspace will be
-	 * confused about which BO the CRTC is scanning out
-	 */
 	fence_put(*f);
-	*f = NULL;
+	return false;
 }
 
 static void amdgpu_flip_work_func(struct work_struct *__work)
@@ -72,13 +70,16 @@ static void amdgpu_flip_work_func(struct work_struct *__work)
 
 	struct drm_crtc *crtc = &amdgpuCrtc->base;
 	unsigned long flags;
-	unsigned i;
-	int vpos, hpos, stat, min_udelay;
+	unsigned i, repcnt = 4;
+	int vpos, hpos, stat, min_udelay = 0;
 	struct drm_vblank_crtc *vblank = &crtc->dev->vblank[work->crtc_id];
 
-	amdgpu_flip_wait_fence(adev, &work->excl);
+	if (amdgpu_flip_handle_fence(work, &work->excl))
+		return;
+
 	for (i = 0; i < work->shared_count; ++i)
-		amdgpu_flip_wait_fence(adev, &work->shared[i]);
+		if (amdgpu_flip_handle_fence(work, &work->shared[i]))
+			return;
 
 	/* We borrow the event spin lock for protecting flip_status */
 	spin_lock_irqsave(&crtc->dev->event_lock, flags);
@@ -96,7 +97,7 @@ static void amdgpu_flip_work_func(struct work_struct *__work)
 	 * In practice this won't execute very often unless on very fast
 	 * machines because the time window for this to happen is very small.
 	 */
-	for (;;) {
+	while (amdgpuCrtc->enabled && --repcnt) {
 		/* GET_DISTANCE_TO_VBLANKSTART returns distance to real vblank
 		 * start in hpos, and to the "fudged earlier" vblank start in
 		 * vpos.
@@ -112,18 +113,30 @@ static void amdgpu_flip_work_func(struct work_struct *__work)
 			break;
 
 		/* Sleep at least until estimated real start of hw vblank */
-		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
 		min_udelay = (-hpos + 1) * max(vblank->linedur_ns / 1000, 5);
+		if (min_udelay > vblank->framedur_ns / 2000) {
+			/* Don't wait ridiculously long - something is wrong */
+			repcnt = 0;
+			break;
+		}
+		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
 		usleep_range(min_udelay, 2 * min_udelay);
 		spin_lock_irqsave(&crtc->dev->event_lock, flags);
 	};
 
-	/* do the flip (mmio) */
-	adev->mode_info.funcs->page_flip(adev, work->crtc_id, work->base);
+	if (!repcnt)
+		DRM_DEBUG_DRIVER("Delay problem on crtc %d: min_udelay %d, "
+				 "framedur %d, linedur %d, stat %d, vpos %d, "
+				 "hpos %d\n", work->crtc_id, min_udelay,
+				 vblank->framedur_ns / 1000,
+				 vblank->linedur_ns / 1000, stat, vpos, hpos);
+
 	/* set the flip status */
 	amdgpuCrtc->pflip_status = AMDGPU_FLIP_SUBMITTED;
-
 	spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
+
+	/* Do the flip (mmio) */
+	adev->mode_info.funcs->page_flip(adev, work->crtc_id, work->base);
 }
 
 /*
@@ -242,7 +255,7 @@ int amdgpu_crtc_page_flip(struct drm_crtc *crtc,
 	/* update crtc fb */
 	crtc->primary->fb = fb;
 	spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
-	queue_work(amdgpu_crtc->pflip_queue, &work->flip_work);
+	amdgpu_flip_work_func(&work->flip_work);
 	return 0;
 
 vblank_cleanup: