From 361eb614723b6019e061c8d343dcbc5a26ceb3b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michel=20D=C3=A4nzer?= <michel.daenzer@amd.com>
Date: Wed, 1 Feb 2012 12:09:55 +0100
Subject: [PATCH 31/87] drm/radeon: Set DESKTOP_HEIGHT register to the
 framebuffer (not mode) height.
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commit 1b61925061660009f5b8047f93c5297e04541273 upstream.

The value of this register is transferred to the V_COUNTER register at the
beginning of vertical blank. V_COUNTER is the reference for VLINE waits and
goes from VIEWPORT_Y_START to VIEWPORT_Y_START+VIEWPORT_HEIGHT during scanout,
so if VIEWPORT_Y_START is not 0, V_COUNTER actually went backwards at the
beginning of vertical blank, and VLINE waits excluding the whole scanout area
could never finish (possibly only if VIEWPORT_Y_START is larger than the length
of vertical blank in scanlines). Setting DESKTOP_HEIGHT to the framebuffer
height should prevent this for any kind of VLINE wait.

Fixes https://bugs.freedesktop.org/show_bug.cgi?id=45329 .

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/radeon/atombios_crtc.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 2b97262..b30081f 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -1189,7 +1189,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
 	WREG32(EVERGREEN_GRPH_ENABLE + radeon_crtc->crtc_offset, 1);
 
 	WREG32(EVERGREEN_DESKTOP_HEIGHT + radeon_crtc->crtc_offset,
-	       crtc->mode.vdisplay);
+	       target_fb->height);
 	x &= ~3;
 	y &= ~1;
 	WREG32(EVERGREEN_VIEWPORT_START + radeon_crtc->crtc_offset,
@@ -1358,7 +1358,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
 	WREG32(AVIVO_D1GRPH_ENABLE + radeon_crtc->crtc_offset, 1);
 
 	WREG32(AVIVO_D1MODE_DESKTOP_HEIGHT + radeon_crtc->crtc_offset,
-	       crtc->mode.vdisplay);
+	       target_fb->height);
 	x &= ~3;
 	y &= ~1;
 	WREG32(AVIVO_D1MODE_VIEWPORT_START + radeon_crtc->crtc_offset,
-- 
1.7.9.4

