| Message ID | 20250415-hblank-v2-1-1a23e9d97360@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Rework/Correction on minimum hblank calculation | expand |
On Tue, Apr 15, 2025 at 01:25:07PM +0530, Arun R Murthy wrote: > Unify the function to calculate the link symbol cycles for both dsc and > non-dsc case and export the function so that it can be used in the > respective platform display drivers for other calculations. > > v2: unify the fn for both dsc and non-dsc case (Imre) > > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com> > --- > drivers/gpu/drm/display/drm_dp_helper.c | 47 ++++++++++++++++----------------- > include/drm/display/drm_dp_helper.h | 3 +++ > 2 files changed, 26 insertions(+), 24 deletions(-) > > diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c > index 57828f2b7b5a0582ca4a6f2a9be2d5909fe8ad24..1a5ff9ba6505f312ee41eb3bcc8b53d318411c03 100644 > --- a/drivers/gpu/drm/display/drm_dp_helper.c > +++ b/drivers/gpu/drm/display/drm_dp_helper.c > @@ -4393,25 +4393,30 @@ EXPORT_SYMBOL(drm_panel_dp_aux_backlight); > #endif > > /* See DP Standard v2.1 2.6.4.4.1.1, 2.8.4.4, 2.8.7 */ > -static int drm_dp_link_symbol_cycles(int lane_count, int pixels, int bpp_x16, > - int symbol_size, bool is_mst) > +/** > + * drm_dp_link_symbol_cycles - calculate the link symbol count > + * @lane_coount: DP link lane count > + * @pixels: horizontal active pixels > + * @bpp_x16: bits per pixel in .4 binary fixed format > + * @symbol_size: DP symbol size > + * @is_mst: is mst or sst > + * @slice_count: number of slices > + * > + * Calculate the link symbol cycles for both dsc and non dsc case and > + * return the count. > + */ > +int drm_dp_link_symbol_cycles(int lane_count, int pixels, int bpp_x16, > + int symbol_size, bool is_mst, int slice_count) > { > - int cycles = DIV_ROUND_UP(pixels * bpp_x16, 16 * symbol_size * lane_count); > + int pix = slice_count ? DIV_ROUND_UP(pixels, slice_count) : pixels; > + int cycles = DIV_ROUND_UP(pix * bpp_x16, 16 * symbol_size * lane_count); > int align = is_mst ? 4 / lane_count : 1; > + int slice_data_cycles = ALIGN(cycles, align); > > - return ALIGN(cycles, align); > -} > - > -static int drm_dp_link_dsc_symbol_cycles(int lane_count, int pixels, int slice_count, > - int bpp_x16, int symbol_size, bool is_mst) > -{ > - int slice_pixels = DIV_ROUND_UP(pixels, slice_count); > - int slice_data_cycles = drm_dp_link_symbol_cycles(lane_count, slice_pixels, > - bpp_x16, symbol_size, is_mst); > - int slice_eoc_cycles = is_mst ? 4 / lane_count : 1; > - > - return slice_count * (slice_data_cycles + slice_eoc_cycles); > + return slice_count ? (slice_count * (slice_data_cycles + align)) : > + slice_data_cycles; I'd like to preserve in the code what the DSC EOC cycles are and the way the data symbol cycles are calculated could be kept as-is. So could you instead do the following, renaming drm_dp_link_symbol_cycles() to drm_dp_link_data_symbol_cycles()?: -static int drm_dp_link_dsc_symbol_cycles(int lane_count, int pixels, int slice_count, - int bpp_x16, int symbol_size, bool is_mst) int drm_dp_link_symbol_cycles(int lane_count, int pixels, int dsc_slice_count, + int bpp_x16, int symbol_size, bool is_mst) { + int slice_count = dsc_slice_count ? : 1; int slice_pixels = DIV_ROUND_UP(pixels, slice_count); - int slice_data_cycles = drm_dp_link_symbol_cycles(lane_count, slice_pixels, - bpp_x16, symbol_size, is_mst); - int slice_eoc_cycles = is_mst ? 4 / lane_count : 1; + int slice_data_cycles = drm_dp_link_data_symbol_cycles(lane_count, slice_pixels, + bpp_x16, symbol_size, is_mst); + int slice_eoc_cycles = 0; + + if (dsc_slice_count) + slice_eoc_cycles = is_mst ? 4 / lane_count : 1; return slice_count * (slice_data_cycles + slice_eoc_cycles); } > } > +EXPORT_SYMBOL(drm_dp_link_symbol_cycles); > > /** > * drm_dp_bw_overhead - Calculate the BW overhead of a DP link stream > @@ -4486,15 +4491,9 @@ int drm_dp_bw_overhead(int lane_count, int hactive, > WARN_ON((flags & DRM_DP_BW_OVERHEAD_UHBR) && > (flags & DRM_DP_BW_OVERHEAD_FEC)); > > - if (flags & DRM_DP_BW_OVERHEAD_DSC) > - symbol_cycles = drm_dp_link_dsc_symbol_cycles(lane_count, hactive, > - dsc_slice_count, > - bpp_x16, symbol_size, > - is_mst); > - else > - symbol_cycles = drm_dp_link_symbol_cycles(lane_count, hactive, > - bpp_x16, symbol_size, > - is_mst); > + symbol_cycles = drm_dp_link_symbol_cycles(lane_count, hactive, > + bpp_x16, symbol_size, > + is_mst, dsc_slice_count); > > return DIV_ROUND_UP_ULL(mul_u32_u32(symbol_cycles * symbol_size * lane_count, > overhead * 16), > diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h > index d9614e2c89397536f44bb7258e894628ae1dccc9..22ae37e7870f1008acfc980a9b46d8dea1fbbe10 100644 > --- a/include/drm/display/drm_dp_helper.h > +++ b/include/drm/display/drm_dp_helper.h > @@ -972,4 +972,7 @@ int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes); > > ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp *sdp); > > +int drm_dp_link_symbol_cycles(int lane_count, int pixels, int bpp_x16, > + int symbol_size, bool is_mst, int slice_count); > + > #endif /* _DRM_DP_HELPER_H_ */ > > -- > 2.25.1 >
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index 57828f2b7b5a0582ca4a6f2a9be2d5909fe8ad24..1a5ff9ba6505f312ee41eb3bcc8b53d318411c03 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -4393,25 +4393,30 @@ EXPORT_SYMBOL(drm_panel_dp_aux_backlight); #endif /* See DP Standard v2.1 2.6.4.4.1.1, 2.8.4.4, 2.8.7 */ -static int drm_dp_link_symbol_cycles(int lane_count, int pixels, int bpp_x16, - int symbol_size, bool is_mst) +/** + * drm_dp_link_symbol_cycles - calculate the link symbol count + * @lane_coount: DP link lane count + * @pixels: horizontal active pixels + * @bpp_x16: bits per pixel in .4 binary fixed format + * @symbol_size: DP symbol size + * @is_mst: is mst or sst + * @slice_count: number of slices + * + * Calculate the link symbol cycles for both dsc and non dsc case and + * return the count. + */ +int drm_dp_link_symbol_cycles(int lane_count, int pixels, int bpp_x16, + int symbol_size, bool is_mst, int slice_count) { - int cycles = DIV_ROUND_UP(pixels * bpp_x16, 16 * symbol_size * lane_count); + int pix = slice_count ? DIV_ROUND_UP(pixels, slice_count) : pixels; + int cycles = DIV_ROUND_UP(pix * bpp_x16, 16 * symbol_size * lane_count); int align = is_mst ? 4 / lane_count : 1; + int slice_data_cycles = ALIGN(cycles, align); - return ALIGN(cycles, align); -} - -static int drm_dp_link_dsc_symbol_cycles(int lane_count, int pixels, int slice_count, - int bpp_x16, int symbol_size, bool is_mst) -{ - int slice_pixels = DIV_ROUND_UP(pixels, slice_count); - int slice_data_cycles = drm_dp_link_symbol_cycles(lane_count, slice_pixels, - bpp_x16, symbol_size, is_mst); - int slice_eoc_cycles = is_mst ? 4 / lane_count : 1; - - return slice_count * (slice_data_cycles + slice_eoc_cycles); + return slice_count ? (slice_count * (slice_data_cycles + align)) : + slice_data_cycles; } +EXPORT_SYMBOL(drm_dp_link_symbol_cycles); /** * drm_dp_bw_overhead - Calculate the BW overhead of a DP link stream @@ -4486,15 +4491,9 @@ int drm_dp_bw_overhead(int lane_count, int hactive, WARN_ON((flags & DRM_DP_BW_OVERHEAD_UHBR) && (flags & DRM_DP_BW_OVERHEAD_FEC)); - if (flags & DRM_DP_BW_OVERHEAD_DSC) - symbol_cycles = drm_dp_link_dsc_symbol_cycles(lane_count, hactive, - dsc_slice_count, - bpp_x16, symbol_size, - is_mst); - else - symbol_cycles = drm_dp_link_symbol_cycles(lane_count, hactive, - bpp_x16, symbol_size, - is_mst); + symbol_cycles = drm_dp_link_symbol_cycles(lane_count, hactive, + bpp_x16, symbol_size, + is_mst, dsc_slice_count); return DIV_ROUND_UP_ULL(mul_u32_u32(symbol_cycles * symbol_size * lane_count, overhead * 16), diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index d9614e2c89397536f44bb7258e894628ae1dccc9..22ae37e7870f1008acfc980a9b46d8dea1fbbe10 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -972,4 +972,7 @@ int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes); ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp *sdp); +int drm_dp_link_symbol_cycles(int lane_count, int pixels, int bpp_x16, + int symbol_size, bool is_mst, int slice_count); + #endif /* _DRM_DP_HELPER_H_ */
Unify the function to calculate the link symbol cycles for both dsc and non-dsc case and export the function so that it can be used in the respective platform display drivers for other calculations. v2: unify the fn for both dsc and non-dsc case (Imre) Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com> --- drivers/gpu/drm/display/drm_dp_helper.c | 47 ++++++++++++++++----------------- include/drm/display/drm_dp_helper.h | 3 +++ 2 files changed, 26 insertions(+), 24 deletions(-)