drm/amd/display: use proper formula to calculate bandwidth from timing

[why]
The existing calculation uses a wrong formula to
calculate bandwidth from timing.

[how]
Expose the existing proper function that calculates the bandwidth,
so dc_link can use it to calculate timing bandwidth correctly.

Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 2 insertions, 49 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 528c9625b5c0..491d13d27e9e 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -1533,53 +1533,6 @@ static bool decide_fallback_link_setting(
 	return true;
 }
 
-static uint32_t bandwidth_in_kbps_from_timing(
-	const struct dc_crtc_timing *timing)
-{
-	uint32_t bits_per_channel = 0;
-	uint32_t kbps;
-
-	switch (timing->display_color_depth) {
-	case COLOR_DEPTH_666:
-		bits_per_channel = 6;
-		break;
-	case COLOR_DEPTH_888:
-		bits_per_channel = 8;
-		break;
-	case COLOR_DEPTH_101010:
-		bits_per_channel = 10;
-		break;
-	case COLOR_DEPTH_121212:
-		bits_per_channel = 12;
-		break;
-	case COLOR_DEPTH_141414:
-		bits_per_channel = 14;
-		break;
-	case COLOR_DEPTH_161616:
-		bits_per_channel = 16;
-		break;
-	default:
-		break;
-	}
-
-	ASSERT(bits_per_channel != 0);
-
-	kbps = timing->pix_clk_100hz / 10;
-	kbps *= bits_per_channel;
-
-	if (timing->flags.Y_ONLY != 1) {
-		/*Only YOnly make reduce bandwidth by 1/3 compares to RGB*/
-		kbps *= 3;
-		if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR420)
-			kbps /= 2;
-		else if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR422)
-			kbps = kbps * 2 / 3;
-	}
-
-	return kbps;
-
-}
-
 static uint32_t bandwidth_in_kbps_from_link_settings(
 	const struct dc_link_settings *link_setting)
 {
@@ -1620,7 +1573,7 @@ bool dp_validate_mode_timing(
 		link_setting = &link->verified_link_cap;
 	*/
 
-	req_bw = bandwidth_in_kbps_from_timing(timing);
+	req_bw = dc_bandwidth_in_kbps_from_timing(timing);
 	max_bw = bandwidth_in_kbps_from_link_settings(link_setting);
 
 	if (req_bw <= max_bw) {
@@ -1739,7 +1692,7 @@ void decide_link_settings(struct dc_stream_state *stream,
 	struct dc_link *link;
 	uint32_t req_bw;
 
-	req_bw = bandwidth_in_kbps_from_timing(&stream->timing);
+	req_bw = dc_bandwidth_in_kbps_from_timing(&stream->timing);
 
 	link = stream->link;