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)
v3: rename drm_dp_link_symbol_cycles to drm_dp_link_data_symbol_cycles
retain slice_eoc_cycles as is (Imre)
Signed-off-by: Arun R Murthy <arun.r.mur...@intel.com>
---
drivers/gpu/drm/display/drm_dp_helper.c | 53 +++++++++++++++++----------------
include/drm/display/drm_dp_helper.h | 2 ++
2 files changed, 29 insertions(+), 26 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index
57828f2b7b5a0582ca4a6f2a9be2d5909fe8ad24..5ce8ccc3310fb71b39ea5f74c4022474c180f727
100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4392,26 +4392,33 @@ 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 cycles = DIV_ROUND_UP(pixels * bpp_x16, 16 * symbol_size *
lane_count);
- int align = is_mst ? 4 / lane_count : 1;
-
- 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);
+/**
+ * drm_dp_link_data_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_data_symbol_cycles(int lane_count, int pixels, int bpp_x16,
+ int symbol_size, bool is_mst, int
slice_count)
+{
+ int slice_pixels = slice_count ? DIV_ROUND_UP(pixels, slice_count) :
+ pixels;
+ int cycles = DIV_ROUND_UP(slice_pixels * bpp_x16,
+ (6 * symbol_size * lane_count));
+ int slice_data_cycles = ALIGN(cycles, is_mst ? (4 / lane_count) : 1);
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 + slice_eoc_cycles)) :
+ slice_data_cycles;
}
+EXPORT_SYMBOL(drm_dp_link_data_symbol_cycles);
/**
* drm_dp_bw_overhead - Calculate the BW overhead of a DP link stream
@@ -4486,15 +4493,9 @@ 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_data_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..98bbbe98e5bc0ce0f9cdf513b2c5ea90bb5caffb
100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -971,5 +971,7 @@ int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
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_data_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
