| Message ID | 20250408-hblank-v1-1-4ba17aebee65@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Rework/Correction on minimum hblank calculation | expand |
On Tue, Apr 08, 2025 at 09:40:34AM +0530, Arun R Murthy wrote: > Link symbol cycles are required for the calculation of the minimum > HBlank calculation. > > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com> > --- > drivers/gpu/drm/display/drm_dp_helper.c | 10 ++++++---- > include/drm/display/drm_dp_helper.h | 5 +++++ > 2 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c > index 57828f2b7b5a0582ca4a6f2a9be2d5909fe8ad24..488aaef61e3aa8b25975dfc98cbccdf5b7f083f8 100644 > --- a/drivers/gpu/drm/display/drm_dp_helper.c > +++ b/drivers/gpu/drm/display/drm_dp_helper.c > @@ -4393,17 +4393,18 @@ 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) > +int drm_dp_link_symbol_cycles(int lane_count, int pixels, int bpp_x16, > + int symbol_size, bool is_mst) > { > int cycles = DIV_ROUND_UP(pixels * bpp_x16, 16 * symbol_size * lane_count); > int align = is_mst ? 4 / lane_count : 1; > > return ALIGN(cycles, align); > } > +EXPORT_SYMBOL(drm_dp_link_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_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, Could you simplify this i/f by calculating the DSC/non-DSC specific symbol count based on whether the passed in dsc_slice_count is non-zero or zero respectively (renaming this function to drm_dp_link_symbol_cycles() and the original drm_dp_link_symbol_cycles() to stg else)? That way you'd need to export only one function and drm_dp_bw_overhead() would also get simplified. > @@ -4412,6 +4413,7 @@ static int drm_dp_link_dsc_symbol_cycles(int lane_count, int pixels, int slice_c > > return slice_count * (slice_data_cycles + slice_eoc_cycles); > } > +EXPORT_SYMBOL(drm_dp_link_dsc_symbol_cycles); > > /** > * drm_dp_bw_overhead - Calculate the BW overhead of a DP link stream > diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h > index d9614e2c89397536f44bb7258e894628ae1dccc9..f6bfa3b74810438b837540dccb08a987bcdb5d03 100644 > --- a/include/drm/display/drm_dp_helper.h > +++ b/include/drm/display/drm_dp_helper.h > @@ -972,4 +972,9 @@ 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 drm_dp_link_dsc_symbol_cycles(int lane_count, int pixels, int slice_count, > + int bpp_x16, int symbol_size, bool is_mst); > + > #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..488aaef61e3aa8b25975dfc98cbccdf5b7f083f8 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -4393,17 +4393,18 @@ 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) +int drm_dp_link_symbol_cycles(int lane_count, int pixels, int bpp_x16, + int symbol_size, bool is_mst) { int cycles = DIV_ROUND_UP(pixels * bpp_x16, 16 * symbol_size * lane_count); int align = is_mst ? 4 / lane_count : 1; return ALIGN(cycles, align); } +EXPORT_SYMBOL(drm_dp_link_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_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, @@ -4412,6 +4413,7 @@ static int drm_dp_link_dsc_symbol_cycles(int lane_count, int pixels, int slice_c return slice_count * (slice_data_cycles + slice_eoc_cycles); } +EXPORT_SYMBOL(drm_dp_link_dsc_symbol_cycles); /** * drm_dp_bw_overhead - Calculate the BW overhead of a DP link stream diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index d9614e2c89397536f44bb7258e894628ae1dccc9..f6bfa3b74810438b837540dccb08a987bcdb5d03 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -972,4 +972,9 @@ 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 drm_dp_link_dsc_symbol_cycles(int lane_count, int pixels, int slice_count, + int bpp_x16, int symbol_size, bool is_mst); + #endif /* _DRM_DP_HELPER_H_ */
Link symbol cycles are required for the calculation of the minimum HBlank calculation. Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com> --- drivers/gpu/drm/display/drm_dp_helper.c | 10 ++++++---- include/drm/display/drm_dp_helper.h | 5 +++++ 2 files changed, 11 insertions(+), 4 deletions(-)