diff options
| author | Imre Deak <imre.deak@intel.com> | 2023-11-16 15:18:40 +0200 |
|---|---|---|
| committer | Imre Deak <imre.deak@intel.com> | 2023-11-21 16:32:44 +0200 |
| commit | b9de01d85a62ddc4fce8f28eeba64b5682431158 (patch) | |
| tree | d377277f6f9d0c1b27bd8943ed13718ac32f0372 /drivers | |
| parent | 5ee4badb4b195bd871ba6d5a2d43aac03587230a (diff) | |
drm/i915/dp: Simplify intel_dp_max_data_rate()
Simplify intel_dp_max_data_rate() using
drm_dp_bw_channel_coding_efficiency() to calculate the max data rate for
both DP1.4 and UHBR link rates. This trades a redundant multiply/divide
for readability.
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231116131841.1588781-11-imre.deak@intel.com
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 7fd883b954a6..6d5a794b6b71 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -405,29 +405,27 @@ int intel_dp_effective_data_rate(int pixel_clock, int bpp_x16, int intel_dp_max_data_rate(int max_link_rate, int max_lanes) { - if (max_link_rate >= 1000000) { - /* - * UHBR rates always use 128b/132b channel encoding, and have - * 97.71% data bandwidth efficiency. Consider max_link_rate the - * link bit rate in units of 10000 bps. - */ - int max_link_rate_kbps = max_link_rate * 10; - - max_link_rate_kbps = DIV_ROUND_DOWN_ULL(mul_u32_u32(max_link_rate_kbps, 9671), 10000); - max_link_rate = max_link_rate_kbps / 8; - } + int ch_coding_efficiency = + drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(max_link_rate)); + int max_link_rate_kbps = max_link_rate * 10; /* + * UHBR rates always use 128b/132b channel encoding, and have + * 97.71% data bandwidth efficiency. Consider max_link_rate the + * link bit rate in units of 10000 bps. + */ + /* * Lower than UHBR rates always use 8b/10b channel encoding, and have * 80% data bandwidth efficiency for SST non-FEC. However, this turns - * out to be a nop by coincidence, and can be skipped: + * out to be a nop by coincidence: * * int max_link_rate_kbps = max_link_rate * 10; * max_link_rate_kbps = DIV_ROUND_DOWN_ULL(max_link_rate_kbps * 8, 10); * max_link_rate = max_link_rate_kbps / 8; */ - - return max_link_rate * max_lanes; + return DIV_ROUND_DOWN_ULL(mul_u32_u32(max_link_rate_kbps * max_lanes, + ch_coding_efficiency), + 1000000 * 8); } bool intel_dp_can_bigjoiner(struct intel_dp *intel_dp) |