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

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[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>
This commit is contained in:
Wenjing Liu 2019-03-21 13:05:36 -04:00 committed by Alex Deucher
parent e5490464f4
commit e49f69363a
3 changed files with 51 additions and 50 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
drivers/gpu/drm/amd/display/dc/core/dc_link.c
View File

@ -2321,7 +2321,7 @@ static struct fixed31_32 get_pbn_from_timing(struct pipe_ctx *pipe_ctx)
uint32_t denominator;
bpc = get_color_depth(pipe_ctx->stream_res.pix_clk_params.color_depth);
kbps = pipe_ctx->stream_res.pix_clk_params.requested_pix_clk_100hz / 10 * bpc * 3;
kbps = dc_bandwidth_in_kbps_from_timing(&pipe_ctx->stream->timing);
/*
* margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
@ -2736,3 +2736,49 @@ void dc_link_enable_hpd_filter(struct dc_link *link, bool enable)
}
}
uint32_t dc_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;
}

51
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
View File

@ -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;

2
drivers/gpu/drm/amd/display/dc/dc_link.h
View File

@ -252,4 +252,6 @@ bool dc_submit_i2c(
uint32_t link_index,
struct i2c_command *cmd);
uint32_t dc_bandwidth_in_kbps_from_timing(
const struct dc_crtc_timing *timing);
#endif /* DC_LINK_H_ */