[PATCH 10/19] drm/amd/display: Defer cursor update around VUPDATE for all ASIC

Aurabindo Pillai aurabindo.pillai at amd.com
Wed Apr 22 22:07:56 UTC 2020


From: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>

[Why]
Fixes the following scenario:

- Flip has been prepared sometime during the frame, update pending
- Cursor update happens right when VUPDATE would happen
- OPTC lock acquired, VUPDATE is blocked until next frame
- Flip is delayed potentially infinitely

With the igt at kms_cursor_legacy cursor-vs-flip-legacy test we can
observe nearly *13* frames of delay for some flips on Navi.

[How]
Apply the Raven workaround generically. When close enough to VUPDATE
block cursor updates from occurring from the dc_stream_set_cursor_*
helpers.

This could perhaps be a little smarter by checking if there were
pending updates or flips earlier in the frame on the HUBP side before
applying the delay, but this should be fine for now.

This fixes the kms_cursor_legacy test.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr at amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai at amd.com>
---
 .../gpu/drm/amd/display/dc/core/dc_stream.c   | 28 +++++++++----------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
index 6ddbb00ed37a..8c20e9e907b2 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -239,24 +239,24 @@ static void delay_cursor_until_vupdate(struct pipe_ctx *pipe_ctx, struct dc *dc)
 	struct dc_stream_state *stream = pipe_ctx->stream;
 	unsigned int us_per_line;
 
-	if (stream->ctx->asic_id.chip_family == FAMILY_RV &&
-			ASICREV_IS_RAVEN(stream->ctx->asic_id.hw_internal_rev)) {
+	if (!dc->hwss.get_vupdate_offset_from_vsync)
+		return;
 
-		vupdate_line = dc->hwss.get_vupdate_offset_from_vsync(pipe_ctx);
-		if (!dc_stream_get_crtc_position(dc, &stream, 1, &vpos, &nvpos))
-			return;
+	vupdate_line = dc->hwss.get_vupdate_offset_from_vsync(pipe_ctx);
+	if (!dc_stream_get_crtc_position(dc, &stream, 1, &vpos, &nvpos))
+		return;
 
-		if (vpos >= vupdate_line)
-			return;
+	if (vpos >= vupdate_line)
+		return;
 
-		us_per_line = stream->timing.h_total * 10000 / stream->timing.pix_clk_100hz;
-		lines_to_vupdate = vupdate_line - vpos;
-		us_to_vupdate = lines_to_vupdate * us_per_line;
+	us_per_line =
+		stream->timing.h_total * 10000 / stream->timing.pix_clk_100hz;
+	lines_to_vupdate = vupdate_line - vpos;
+	us_to_vupdate = lines_to_vupdate * us_per_line;
 
-		/* 70 us is a conservative estimate of cursor update time*/
-		if (us_to_vupdate < 70)
-			udelay(us_to_vupdate);
-	}
+	/* 70 us is a conservative estimate of cursor update time*/
+	if (us_to_vupdate < 70)
+		udelay(us_to_vupdate);
 #endif
 }
 
-- 
2.17.1



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