drm/amd/display: Don't share clk source between DP and HDMI

[why]
Prevent clock source sharing between HDMI and DP connectors.
DP shouldn't be sharing its ref clock with phy clock,
which caused an issue of older ASICS booting up with multiple
diplays plugged in.

[how]
Add an extra check that would prevent HDMI and DP sharing clk.

Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Reviewed-by: Hersen Wu <hersenxs.wu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

4 files changed, 26 insertions, 2 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 2e65715f76a1..4ca41d6e3bcf 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -330,6 +330,9 @@ bool resource_are_streams_timing_synchronizable(
 				!= stream2->timing.pix_clk_khz)
 		return false;
 
+	if (stream1->clamping.c_depth != stream2->clamping.c_depth)
+		return false;
+
 	if (stream1->phy_pix_clk != stream2->phy_pix_clk
 			&& (!dc_is_dp_signal(stream1->signal)
 			|| !dc_is_dp_signal(stream2->signal)))
@@ -337,6 +340,20 @@ bool resource_are_streams_timing_synchronizable(
 
 	return true;
 }
+static bool is_dp_and_hdmi_sharable(
+		struct dc_stream_state *stream1,
+		struct dc_stream_state *stream2)
+{
+	if (stream1->ctx->dc->caps.disable_dp_clk_share)
+		return false;
+
+	if (stream1->clamping.c_depth != COLOR_DEPTH_888 ||
+	    stream2->clamping.c_depth != COLOR_DEPTH_888)
+	return false;
+
+	return true;
+
+}
 
 static bool is_sharable_clk_src(
 	const struct pipe_ctx *pipe_with_clk_src,
@@ -348,7 +365,10 @@ static bool is_sharable_clk_src(
 	if (pipe_with_clk_src->stream->signal == SIGNAL_TYPE_VIRTUAL)
 		return false;
 
-	if (dc_is_dp_signal(pipe_with_clk_src->stream->signal))
+	if (dc_is_dp_signal(pipe_with_clk_src->stream->signal) ||
+		(dc_is_dp_signal(pipe->stream->signal) &&
+		!is_dp_and_hdmi_sharable(pipe_with_clk_src->stream,
+				     pipe->stream)))
 		return false;
 
 	if (dc_is_hdmi_signal(pipe_with_clk_src->stream->signal)
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 55bcc3bdc6a3..3ecd2d614f41 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -78,6 +78,7 @@ struct dc_caps {
 	bool dual_link_dvi;
 	bool post_blend_color_processing;
 	bool force_dp_tps4_for_cp2520;
+	bool disable_dp_clk_share;
 };
 
 struct dc_dcc_surface_param {
diff --git a/drivers/gpu/drm/amd/display/dc/dce100/dce100_resource.c b/drivers/gpu/drm/amd/display/dc/dce100/dce100_resource.c
index fd2bdae4dcec..3f76e6019546 100644
--- a/drivers/gpu/drm/amd/display/dc/dce100/dce100_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dce100/dce100_resource.c
@@ -919,7 +919,7 @@ static bool construct(
 	dc->caps.i2c_speed_in_khz = 40;
 	dc->caps.max_cursor_size = 128;
 	dc->caps.dual_link_dvi = true;
-
+	dc->caps.disable_dp_clk_share = true;
 	for (i = 0; i < pool->base.pipe_count; i++) {
 		pool->base.timing_generators[i] =
 			dce100_timing_generator_create(
diff --git a/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c b/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c
index dc9f3e9afc33..604c62969ead 100644
--- a/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c
@@ -946,6 +946,7 @@ static bool dce80_construct(
 	}
 
 	dc->caps.max_planes =  pool->base.pipe_count;
+	dc->caps.disable_dp_clk_share = true;
 
 	if (!resource_construct(num_virtual_links, dc, &pool->base,
 			&res_create_funcs))
@@ -1131,6 +1132,7 @@ static bool dce81_construct(
 	}
 
 	dc->caps.max_planes =  pool->base.pipe_count;
+	dc->caps.disable_dp_clk_share = true;
 
 	if (!resource_construct(num_virtual_links, dc, &pool->base,
 			&res_create_funcs))
@@ -1312,6 +1314,7 @@ static bool dce83_construct(
 	}
 
 	dc->caps.max_planes =  pool->base.pipe_count;
+	dc->caps.disable_dp_clk_share = true;
 
 	if (!resource_construct(num_virtual_links, dc, &pool->base,
 			&res_create_funcs))