[RESEND] drm/amd/display: fix audio playing speed up on POLARIS12

[RESEND] drm/amd/display: fix audio playing speed up on POLARIS12

[yaolu]

From: Lu Yao <yaolu@kylinos.cn>

Playing audio/video will speed up when color space is NV12.
For POLARIS12, audio request clock has to be same as
'stream->timing.pix_clk_100hz', so double clock now for it
has been halved in the 'get_pixel_clock_parameters' function.

Signed-off-by: Lu Yao <yaolu@kylinos.cn>
---
 .../amd/display/dc/hwss/dce110/dce110_hwseq.c  | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)
---
Test environment:
  Card: RX550  device id: 0X699F
  Display mode: 4K@60 clock:59400

A similar issue was reported in the community a long time ago,
but it was not dealt with, link as follow:
https://gitlab.freedesktop.org/drm/amd/-/issues/556

Discovered through logs audio_output requested&calculated is half
of stream->timing.pix_clk_100hz before, so I double it.
I'm not sure if this patch modification has correctly solved the
root cause and whether all DCE_VERSION_11_2 have problem or POLARIS12
only, but it's working properly on my machine now.
---

diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
index 24184b4eb352..a93313248db3 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
@@ -1440,13 +1440,21 @@ void build_audio_output(
 
 /*for HDMI, audio ACR is with deep color ratio factor*/
 	if (dc_is_hdmi_tmds_signal(pipe_ctx->stream->signal) &&
-		audio_output->crtc_info.requested_pixel_clock_100Hz ==
-				(stream->timing.pix_clk_100hz)) {
-		if (pipe_ctx->stream_res.pix_clk_params.pixel_encoding == PIXEL_ENCODING_YCBCR420) {
+		pipe_ctx->stream_res.pix_clk_params.pixel_encoding == PIXEL_ENCODING_YCBCR420) {
+		struct hw_asic_id asic_id = stream->link->ctx->asic_id;
+
+		if (asic_id.chip_family == FAMILY_VI &&
+		    ASIC_REV_IS_POLARIS12_V(asic_id.hw_internal_rev)) {
+			audio_output->crtc_info.requested_pixel_clock_100Hz =
+				audio_output->crtc_info.requested_pixel_clock_100Hz*2;
+			audio_output->crtc_info.calculated_pixel_clock_100Hz =
+				pipe_ctx->stream_res.pix_clk_params.requested_pix_clk_100hz*2;
+		} else if (audio_output->crtc_info.requested_pixel_clock_100Hz ==
+			   (stream->timing.pix_clk_100hz)) {
 			audio_output->crtc_info.requested_pixel_clock_100Hz =
-					audio_output->crtc_info.requested_pixel_clock_100Hz/2;
+				audio_output->crtc_info.requested_pixel_clock_100Hz/2;
 			audio_output->crtc_info.calculated_pixel_clock_100Hz =
-					pipe_ctx->stream_res.pix_clk_params.requested_pix_clk_100hz/2;
+				pipe_ctx->stream_res.pix_clk_params.requested_pix_clk_100hz/2;
 
 		}
 	}
-- 
2.25.1

Re: [RESEND] drm/amd/display: fix audio playing speed up on POLARIS12

[Igor Paunovic]

Hi Lu Yao,

I hit the same bug on a Polaris10 (RX 580) with a TV at 3840x2160@60
in YCbCr 4:2:0, and your patch was the only fix I could find, thank
you for posting it.

I have sent a patch that fixes the DTO0 module for HDMI 4:2:0 on
DCE 11.2, 11.22 and 12.x, which should cover POLARIS12 too, and
leaves ACR (N/CTS) as it is:

https://lore.kernel.org/r/20260918100443.23694-1-royalnet026@gmail.com

I could only test Polaris10. If you still have the RX550, a test of
that patch on a tree without yours would help a lot.

An LLM helped me draft this mail.

Thanks,
Igor