drm/i915/dp: Report a rounded-down value as the maximum data rate

Callers of intel_dp_max_data_rate() use the return value as an upper
bound for the BW a given mode requires. As such the rounding shouldn't
result in a bigger value than the actual upper bound. Use round-down
instead of -closest accordingly.

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231116131841.1588781-10-imre.deak@intel.com
This commit is contained in:
Imre Deak
2023-11-16 15:18:39 +02:00
parent 9069b77545
commit 5ee4badb4b

View File

@@ -413,7 +413,7 @@ intel_dp_max_data_rate(int max_link_rate, int max_lanes)
*/
int max_link_rate_kbps = max_link_rate * 10;
max_link_rate_kbps = DIV_ROUND_CLOSEST_ULL(mul_u32_u32(max_link_rate_kbps, 9671), 10000);
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;
}
@@ -423,7 +423,7 @@ intel_dp_max_data_rate(int max_link_rate, int max_lanes)
* out to be a nop by coincidence, and can be skipped:
*
* int max_link_rate_kbps = max_link_rate * 10;
* max_link_rate_kbps = DIV_ROUND_CLOSEST_ULL(max_link_rate_kbps * 8, 10);
* max_link_rate_kbps = DIV_ROUND_DOWN_ULL(max_link_rate_kbps * 8, 10);
* max_link_rate = max_link_rate_kbps / 8;
*/