Fix glitches when moving cursor close to the edge on a rotated screen for drivers with one pipe (without pipe split) by halving dst_x_offset. Reported-by: Xaver Hugl <xaver.hugl@xxxxxxxxx> Signed-off-by: Melissa Wen <mwen@xxxxxxxxxx> --- Hi, I'm not sure if having dst_x_offset (or only for the one pipe case) is the right solution, but it solves the issue on different devices when the pipe split policy is AVOID. Context: Some artifacts appear on HW rotated screen when moving the cursor close to the edge, as reported in: https://gitlab.freedesktop.org/drm/amd/-/issues/2247 This issue was initially reported on DCN 3.0.1 and it's not present in DCN 2.1 by default, for example. These two drivers follow different pipe_split_policy, where there is no pipe split on DCN 3.0.1 (AVOID), but we see pipe splitting on DCN 2.1 (MPC_SPLIT_AVOID_MULT_DISP). Splitting (or not) the pipe changes the way DC calculates cursor movements and its position, as we can see in dcn10_set_cursor_position(). In addition, it's possible to reproduce the same issue found on DCN 3.0.1 by setting DCN 2.1 to avoid pipe splitting plus rotating the screen to any angle different from zero. However, from my experiments, setting DCN 3.0.1 to a different pipe split policy makes the system unstable and causes GPU reset (even though DYNAMIC seems to be the default policy for DC). I see that plugging/unplugging the charger changed the intensity of these artifacts and also see some temporary changes with different power performance settings. Keeping that in mind, I verified calculations and register updates related to cursor movements (dcn10_set_cursor_position(), hubp2_cursor_set_position()), and we can see that some clk values participates in the final result of dst_x_offset. After halving dst_x_offset, the artifacts no longer appear and it solves the problem when pipe splitting is not allowed. This change doesn't affect the correct behavior with more than one pipe, but may affect the optimal setup of bandwidth and clocks. Perhaps, the current values doesn't deliver the right performance when the pipe is not split and halving dst_x_offset is exactly the right step for only one pipe, but not for pipe split. Finally, if this is not the right solution, I appreciate any feedback to address this problem correctly. Thanks, Melissa drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hubp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hubp.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hubp.c index 4566bc7abf17..1ff85d81237e 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hubp.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hubp.c @@ -1018,7 +1018,7 @@ void hubp2_cursor_set_position( src_y_offset = y_pos - (cursor_height - y_hotspot); } - dst_x_offset = (src_x_offset >= 0) ? src_x_offset : 0; + dst_x_offset = (src_x_offset >= 0) ? src_x_offset / 2 : 0; dst_x_offset *= param->ref_clk_khz; dst_x_offset /= param->pixel_clk_khz; -- 2.39.0
