From: George Shen george.shen@amd.com
[ Upstream commit 974764180838516f80a13257da67a1ec6afb87d4 ]
[Why] Current BW calculations do not account for the additional padding added for uncompressed pixel-to-symbol packing.
This results in X.Y being too low for 128b/132b SST streams in certain scenarios. If X.Y is too low, end user can observe image corruption.
[How] Add function to calculate stream overhead to timing BW calculation for 128b/132b SST cases.
Reviewed-by: Wenjing Liu wenjing.liu@amd.com Acked-by: Alan Liu haoping.liu@amd.com Signed-off-by: George Shen george.shen@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/dc.h | 2 + drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c | 42 +++++++++++++++++++++ 2 files changed, 44 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h index 63948170fd6d9..3d4180f7ba349 100644 --- a/drivers/gpu/drm/amd/display/dc/dc.h +++ b/drivers/gpu/drm/amd/display/dc/dc.h @@ -1409,6 +1409,8 @@ struct dc_plane_state *dc_get_surface_for_mpcc(struct dc *dc,
uint32_t dc_get_opp_for_plane(struct dc *dc, struct dc_plane_state *plane);
+void dc_set_disable_128b_132b_stream_overhead(bool disable); + /* The function returns minimum bandwidth required to drive a given timing * return - minimum required timing bandwidth in kbps. */ diff --git a/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c b/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c index 58dd62cce4bb9..aed0d3dafa247 100644 --- a/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c +++ b/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c @@ -40,6 +40,8 @@ static bool dsc_policy_enable_dsc_when_not_needed;
static bool dsc_policy_disable_dsc_stream_overhead;
+static bool disable_128b_132b_stream_overhead; + #ifndef MAX #define MAX(X, Y) ((X) > (Y) ? (X) : (Y)) #endif @@ -47,6 +49,41 @@ static bool dsc_policy_disable_dsc_stream_overhead; #define MIN(X, Y) ((X) < (Y) ? (X) : (Y)) #endif
+/* Need to account for padding due to pixel-to-symbol packing + * for uncompressed 128b/132b streams. + */ +static uint32_t apply_128b_132b_stream_overhead( + const struct dc_crtc_timing *timing, const uint32_t kbps) +{ + uint32_t total_kbps = kbps; + + if (disable_128b_132b_stream_overhead) + return kbps; + + if (!timing->flags.DSC) { + struct fixed31_32 bpp; + struct fixed31_32 overhead_factor; + + bpp = dc_fixpt_from_int(kbps); + bpp = dc_fixpt_div_int(bpp, timing->pix_clk_100hz / 10); + + /* Symbols_per_HActive = HActive * bpp / (4 lanes * 32-bit symbol size) + * Overhead_factor = ceil(Symbols_per_HActive) / Symbols_per_HActive + */ + overhead_factor = dc_fixpt_from_int(timing->h_addressable); + overhead_factor = dc_fixpt_mul(overhead_factor, bpp); + overhead_factor = dc_fixpt_div_int(overhead_factor, 128); + overhead_factor = dc_fixpt_div( + dc_fixpt_from_int(dc_fixpt_ceil(overhead_factor)), + overhead_factor); + + total_kbps = dc_fixpt_ceil( + dc_fixpt_mul_int(overhead_factor, total_kbps)); + } + + return total_kbps; +} + uint32_t dc_bandwidth_in_kbps_from_timing( const struct dc_crtc_timing *timing) { @@ -1165,6 +1202,11 @@ void dc_dsc_policy_set_disable_dsc_stream_overhead(bool disable) dsc_policy_disable_dsc_stream_overhead = disable; }
+void dc_set_disable_128b_132b_stream_overhead(bool disable) +{ + disable_128b_132b_stream_overhead = disable; +} + void dc_dsc_get_default_config_option(const struct dc *dc, struct dc_dsc_config_options *options) { options->dsc_min_slice_height_override = dc->debug.dsc_min_slice_height_override;