> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Imre
> Deak
> Sent: Monday, July 22, 2024 10:25 PM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Subject: [PATCH 07/14] drm/i915/dp: Add a separate function to reduce the link
> parameters
>
> A follow-up patch will add an alternative way to reduce the link parameters in
> BW order on MST links, prepare for that here.
>
> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
LGTM,
Reviewed-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
> ---
> .../drm/i915/display/intel_dp_link_training.c | 39 +++++++++++++++----
> 1 file changed, 31 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> index 58dea87a9fa28..57536ae200b77 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> @@ -1193,6 +1193,36 @@ static int reduce_lane_count(struct intel_dp
> *intel_dp, int current_lane_count)
> return current_lane_count >> 1;
> }
>
> +static bool reduce_link_params_in_rate_lane_order(struct intel_dp *intel_dp,
> + const struct intel_crtc_state
> *crtc_state,
> + int *new_link_rate, int
> *new_lane_count) {
> + int link_rate;
> + int lane_count;
> +
> + lane_count = crtc_state->lane_count;
> + link_rate = reduce_link_rate(intel_dp, crtc_state->port_clock);
> + if (link_rate < 0) {
> + lane_count = reduce_lane_count(intel_dp, crtc_state-
> >lane_count);
> + link_rate = intel_dp_max_common_rate(intel_dp);
> + }
> +
> + if (lane_count < 0)
> + return false;
> +
> + *new_link_rate = link_rate;
> + *new_lane_count = lane_count;
> +
> + return true;
> +}
> +
> +static bool reduce_link_params(struct intel_dp *intel_dp, const struct
> intel_crtc_state *crtc_state,
> + int *new_link_rate, int *new_lane_count) {
> + return reduce_link_params_in_rate_lane_order(intel_dp, crtc_state,
> + new_link_rate,
> new_lane_count); }
> +
> static int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp,
> const struct intel_crtc_state
> *crtc_state) { @@ -1206,14 +1236,7 @@ static int
> intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp,
> return 0;
> }
>
> - new_lane_count = crtc_state->lane_count;
> - new_link_rate = reduce_link_rate(intel_dp, crtc_state->port_clock);
> - if (new_link_rate < 0) {
> - new_lane_count = reduce_lane_count(intel_dp, crtc_state-
> >lane_count);
> - new_link_rate = intel_dp_max_common_rate(intel_dp);
> - }
> -
> - if (new_lane_count < 0)
> + if (!reduce_link_params(intel_dp, crtc_state, &new_link_rate,
> +&new_lane_count))
> return -1;
>
> if (intel_dp_is_edp(intel_dp) &&
> --
> 2.44.2
