4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mario Kleiner <mario.kleiner.de@xxxxxxxxx> commit d63c277dc672e0c568481af043359420fa9d4736 upstream. Avoid big roundoff errors in scanline/hactive durations for high pixel clocks, especially for >= 500 Mhz, and thereby program more accurate display fifo watermarks. Implemented here for DCE 6,8,10,11. Successfully tested on DCE 10 with AMD R9 380 Tonga. Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Mario Kleiner <mario.kleiner.de@xxxxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 10 +++++----- drivers/gpu/drm/amd/amdgpu/dce_v11_0.c | 10 +++++----- drivers/gpu/drm/amd/amdgpu/dce_v8_0.c | 10 +++++----- 3 files changed, 15 insertions(+), 15 deletions(-) --- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c +++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c @@ -1237,14 +1237,14 @@ static void dce_v10_0_program_watermarks { struct drm_display_mode *mode = &amdgpu_crtc->base.mode; struct dce10_wm_params wm_low, wm_high; - u32 pixel_period; + u32 active_time; u32 line_time = 0; u32 latency_watermark_a = 0, latency_watermark_b = 0; u32 tmp, wm_mask, lb_vblank_lead_lines = 0; if (amdgpu_crtc->base.enabled && num_heads && mode) { - pixel_period = 1000000 / (u32)mode->clock; - line_time = min((u32)mode->crtc_htotal * pixel_period, (u32)65535); + active_time = 1000000UL * (u32)mode->crtc_hdisplay / (u32)mode->clock; + line_time = min((u32) (1000000UL * (u32)mode->crtc_htotal / (u32)mode->clock), (u32)65535); /* watermark for high clocks */ if (adev->pm.dpm_enabled) { @@ -1259,7 +1259,7 @@ static void dce_v10_0_program_watermarks wm_high.disp_clk = mode->clock; wm_high.src_width = mode->crtc_hdisplay; - wm_high.active_time = mode->crtc_hdisplay * pixel_period; + wm_high.active_time = active_time; wm_high.blank_time = line_time - wm_high.active_time; wm_high.interlaced = false; if (mode->flags & DRM_MODE_FLAG_INTERLACE) @@ -1298,7 +1298,7 @@ static void dce_v10_0_program_watermarks wm_low.disp_clk = mode->clock; wm_low.src_width = mode->crtc_hdisplay; - wm_low.active_time = mode->crtc_hdisplay * pixel_period; + wm_low.active_time = active_time; wm_low.blank_time = line_time - wm_low.active_time; wm_low.interlaced = false; if (mode->flags & DRM_MODE_FLAG_INTERLACE) --- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c +++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c @@ -1225,14 +1225,14 @@ static void dce_v11_0_program_watermarks { struct drm_display_mode *mode = &amdgpu_crtc->base.mode; struct dce10_wm_params wm_low, wm_high; - u32 pixel_period; + u32 active_time; u32 line_time = 0; u32 latency_watermark_a = 0, latency_watermark_b = 0; u32 tmp, wm_mask, lb_vblank_lead_lines = 0; if (amdgpu_crtc->base.enabled && num_heads && mode) { - pixel_period = 1000000 / (u32)mode->clock; - line_time = min((u32)mode->crtc_htotal * pixel_period, (u32)65535); + active_time = 1000000UL * (u32)mode->crtc_hdisplay / (u32)mode->clock; + line_time = min((u32) (1000000UL * (u32)mode->crtc_htotal / (u32)mode->clock), (u32)65535); /* watermark for high clocks */ if (adev->pm.dpm_enabled) { @@ -1247,7 +1247,7 @@ static void dce_v11_0_program_watermarks wm_high.disp_clk = mode->clock; wm_high.src_width = mode->crtc_hdisplay; - wm_high.active_time = mode->crtc_hdisplay * pixel_period; + wm_high.active_time = active_time; wm_high.blank_time = line_time - wm_high.active_time; wm_high.interlaced = false; if (mode->flags & DRM_MODE_FLAG_INTERLACE) @@ -1286,7 +1286,7 @@ static void dce_v11_0_program_watermarks wm_low.disp_clk = mode->clock; wm_low.src_width = mode->crtc_hdisplay; - wm_low.active_time = mode->crtc_hdisplay * pixel_period; + wm_low.active_time = active_time; wm_low.blank_time = line_time - wm_low.active_time; wm_low.interlaced = false; if (mode->flags & DRM_MODE_FLAG_INTERLACE) --- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c +++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c @@ -1207,14 +1207,14 @@ static void dce_v8_0_program_watermarks( { struct drm_display_mode *mode = &amdgpu_crtc->base.mode; struct dce8_wm_params wm_low, wm_high; - u32 pixel_period; + u32 active_time; u32 line_time = 0; u32 latency_watermark_a = 0, latency_watermark_b = 0; u32 tmp, wm_mask, lb_vblank_lead_lines = 0; if (amdgpu_crtc->base.enabled && num_heads && mode) { - pixel_period = 1000000 / (u32)mode->clock; - line_time = min((u32)mode->crtc_htotal * pixel_period, (u32)65535); + active_time = 1000000UL * (u32)mode->crtc_hdisplay / (u32)mode->clock; + line_time = min((u32) (1000000UL * (u32)mode->crtc_htotal / (u32)mode->clock), (u32)65535); /* watermark for high clocks */ if (adev->pm.dpm_enabled) { @@ -1229,7 +1229,7 @@ static void dce_v8_0_program_watermarks( wm_high.disp_clk = mode->clock; wm_high.src_width = mode->crtc_hdisplay; - wm_high.active_time = mode->crtc_hdisplay * pixel_period; + wm_high.active_time = active_time; wm_high.blank_time = line_time - wm_high.active_time; wm_high.interlaced = false; if (mode->flags & DRM_MODE_FLAG_INTERLACE) @@ -1268,7 +1268,7 @@ static void dce_v8_0_program_watermarks( wm_low.disp_clk = mode->clock; wm_low.src_width = mode->crtc_hdisplay; - wm_low.active_time = mode->crtc_hdisplay * pixel_period; + wm_low.active_time = active_time; wm_low.blank_time = line_time - wm_low.active_time; wm_low.interlaced = false; if (mode->flags & DRM_MODE_FLAG_INTERLACE)