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-rw-r--r--drivers/gpu/drm/amd/display/dc/link/link_dpms.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
index aa0a086aa7fc..b16b2e14312e 100644
--- a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
@@ -1057,18 +1057,21 @@ static struct fixed31_32 get_pbn_from_bw_in_kbps(uint64_t kbps)
uint32_t denominator = 1;
/*
- * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
+ * The 1.006 factor (margin 5300ppm + 300ppm ~ 0.6% as per spec) is not
+ * required when determining PBN/time slot utilization on the link between
+ * us and the branch, since that overhead is already accounted for in
+ * the get_pbn_per_slot function.
+ *
* The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
* common multiplier to render an integer PBN for all link rate/lane
* counts combinations
* calculate
- * peak_kbps *= (1006/1000)
* peak_kbps *= (64/54)
- * peak_kbps *= 8 convert to bytes
+ * peak_kbps /= (8 * 1000) convert to bytes
*/
- numerator = 64 * PEAK_FACTOR_X1000;
- denominator = 54 * 8 * 1000 * 1000;
+ numerator = 64;
+ denominator = 54 * 8 * 1000;
kbps *= numerator;
peak_kbps = dc_fixpt_from_fraction(kbps, denominator);