Thread (440 messages) flat view 440 messages, 8 authors, 2021-09-17
STALE1831d REVIEWED: 1 (0M)

1 review trailer.

[PATCH 5.14 206/432] drm/amd/display: Fix timer_per_pixel unit error

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-09-16 17:32:09
Also in: lkml
Subsystem: amd display core, drm drivers, radeon and amdgpu drm drivers, the rest · Maintainers: Harry Wentland, Leo Li, David Airlie, Simona Vetter, Alex Deucher, Christian König, Linus Torvalds

From: Oliver Logush <redacted>

[ Upstream commit 23e55639b87fb16a9f0f66032ecb57060df6c46c ]

[why]
The units of the time_per_pixel variable were incorrect, this had to be
changed for the code to properly function.

[how]
The change was very straightforward, only required one line of code to
be changed where the calculation was done.

Acked-by: Rodrigo Siqueira <redacted>
Signed-off-by: Oliver Logush <redacted>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
index b173fa3653b5..c78933a9d31c 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
@@ -2462,7 +2462,7 @@ void dcn20_set_mcif_arb_params(
 				wb_arb_params->cli_watermark[k] = get_wm_writeback_urgent(&context->bw_ctx.dml, pipes, pipe_cnt) * 1000;
 				wb_arb_params->pstate_watermark[k] = get_wm_writeback_dram_clock_change(&context->bw_ctx.dml, pipes, pipe_cnt) * 1000;
 			}
-			wb_arb_params->time_per_pixel = 16.0 / context->res_ctx.pipe_ctx[i].stream->phy_pix_clk; /* 4 bit fraction, ms */
+			wb_arb_params->time_per_pixel = 16.0 * 1000 / (context->res_ctx.pipe_ctx[i].stream->phy_pix_clk / 1000); /* 4 bit fraction, ms */
 			wb_arb_params->slice_lines = 32;
 			wb_arb_params->arbitration_slice = 2;
 			wb_arb_params->max_scaled_time = dcn20_calc_max_scaled_time(wb_arb_params->time_per_pixel,
-- 
2.30.2


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