drm/radeon: update line buffer allocation for dce4.1/5
We need to allocate line buffer to each display when
setting up the watermarks. Failure to do so can lead
to a blank screen. This fixes blank screen problems
on dce4.1/5 asics.
Based on an initial fix from:
Jay Cornwall <jay.cornwall@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 2ca9f13..1832136 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -1812,7 +1812,8 @@
struct drm_display_mode *mode,
struct drm_display_mode *other_mode)
{
- u32 tmp;
+ u32 tmp, buffer_alloc, i;
+ u32 pipe_offset = radeon_crtc->crtc_id * 0x20;
/*
* Line Buffer Setup
* There are 3 line buffers, each one shared by 2 display controllers.
@@ -1835,18 +1836,34 @@
* non-linked crtcs for maximum line buffer allocation.
*/
if (radeon_crtc->base.enabled && mode) {
- if (other_mode)
+ if (other_mode) {
tmp = 0; /* 1/2 */
- else
+ buffer_alloc = 1;
+ } else {
tmp = 2; /* whole */
- } else
+ buffer_alloc = 2;
+ }
+ } else {
tmp = 0;
+ buffer_alloc = 0;
+ }
/* second controller of the pair uses second half of the lb */
if (radeon_crtc->crtc_id % 2)
tmp += 4;
WREG32(DC_LB_MEMORY_SPLIT + radeon_crtc->crtc_offset, tmp);
+ if (ASIC_IS_DCE41(rdev) || ASIC_IS_DCE5(rdev)) {
+ WREG32(PIPE0_DMIF_BUFFER_CONTROL + pipe_offset,
+ DMIF_BUFFERS_ALLOCATED(buffer_alloc));
+ for (i = 0; i < rdev->usec_timeout; i++) {
+ if (RREG32(PIPE0_DMIF_BUFFER_CONTROL + pipe_offset) &
+ DMIF_BUFFERS_ALLOCATED_COMPLETED)
+ break;
+ udelay(1);
+ }
+ }
+
if (radeon_crtc->base.enabled && mode) {
switch (tmp) {
case 0: