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 --- drivers/gpu/drm/radeon/evergreen.c | 25 +++++++++++++++++++++---- drivers/gpu/drm/radeon/evergreend.h | 4 ++++ 2 files changed, 25 insertions(+), 4 deletions(-)
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 @@ static u32 evergreen_line_buffer_adjust(struct radeon_device *rdev, 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 @@ static u32 evergreen_line_buffer_adjust(struct radeon_device *rdev, * 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: diff --git a/drivers/gpu/drm/radeon/evergreend.h b/drivers/gpu/drm/radeon/evergreend.h index 430997a..8768fd6 100644 --- a/drivers/gpu/drm/radeon/evergreend.h +++ b/drivers/gpu/drm/radeon/evergreend.h @@ -1160,6 +1160,10 @@ # define LATENCY_LOW_WATERMARK(x) ((x) << 0) # define LATENCY_HIGH_WATERMARK(x) ((x) << 16)
+#define PIPE0_DMIF_BUFFER_CONTROL 0x0ca0 +# define DMIF_BUFFERS_ALLOCATED(x) ((x) << 0) +# define DMIF_BUFFERS_ALLOCATED_COMPLETED (1 << 4) + #define IH_RB_CNTL 0x3e00 # define IH_RB_ENABLE (1 << 0) # define IH_IB_SIZE(x) ((x) << 1) /* log2 */