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@xxxxxxxxxxxxxxx>
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_dp.c | 26 ++++++++++++-------------
1 file 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 209c27167e057..a93e8f6429d85 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)
--
2.39.2
