drm/amd/display: take max dsc stream bandwidth overhead into account

[why]
As hardware team suggested that we need to add a max dsc bw overhead
into existing stream bandwidth when DSC is used.
The formula as below:

max_dsc_bw_overhead =
v_addressable * slice_count * 256 bit * pixel clock / v_total / h_total

effective stream bandwidth = pixel clock * bpp

stream bandwidth = effective stream bandwidth + dsc stream overhead

Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Reviewed-by: Eric Bernstein <Eric.Bernstein@amd.com>
Acked-by: Wayne Lin <waynelin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 0 insertions, 43 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/dsc/rc_calc.c b/drivers/gpu/drm/amd/display/dc/dsc/rc_calc.c
index c6a1cd80aeae..7b294f637881 100644
--- a/drivers/gpu/drm/amd/display/dc/dsc/rc_calc.c
+++ b/drivers/gpu/drm/amd/display/dc/dsc/rc_calc.c
@@ -284,26 +284,6 @@ static u32 _do_bytes_per_pixel_calc(int slice_width, u16 drm_bpp,
 	return bytes_per_pixel;
 }
 
-static u32 _do_calc_dsc_bpp_x16(u32 stream_bandwidth_kbps, u32 pix_clk_100hz,
-				u32 bpp_increment_div)
-{
-	u32 dsc_target_bpp_x16;
-	float f_dsc_target_bpp;
-	float f_stream_bandwidth_100bps;
-	// bpp_increment_div is actually precision
-	u32 precision = bpp_increment_div;
-
-	f_stream_bandwidth_100bps = stream_bandwidth_kbps * 10.0f;
-	f_dsc_target_bpp = f_stream_bandwidth_100bps / pix_clk_100hz;
-
-	// Round down to the nearest precision stop to bring it into DSC spec
-	// range
-	dsc_target_bpp_x16 = (u32)(f_dsc_target_bpp * precision);
-	dsc_target_bpp_x16 = (dsc_target_bpp_x16 * 16) / precision;
-
-	return dsc_target_bpp_x16;
-}
-
 /**
  * calc_rc_params - reads the user's cmdline mode
  * @rc: DC internal DSC parameters
@@ -367,26 +347,3 @@ u32 calc_dsc_bytes_per_pixel(const struct drm_dsc_config *pps)
 	DC_FP_END();
 	return ret;
 }
-
-/**
- * calc_dsc_bpp_x16 - retrieve the dsc bits per pixel
- * @stream_bandwidth_kbps:
- * @pix_clk_100hz:
- * @bpp_increment_div:
- *
- * Calculate the total of bits per pixel for DSC configuration.
- *
- * @note This calculation requires float point operation, most of it executes
- * under kernel_fpu_{begin,end}.
- */
-u32 calc_dsc_bpp_x16(u32 stream_bandwidth_kbps, u32 pix_clk_100hz,
-		     u32 bpp_increment_div)
-{
-	u32 dsc_bpp;
-
-	DC_FP_START();
-	dsc_bpp =  _do_calc_dsc_bpp_x16(stream_bandwidth_kbps, pix_clk_100hz,
-					bpp_increment_div);
-	DC_FP_END();
-	return dsc_bpp;
-}