On Wed, Jan 28, 2026 at 07:36:34PM +0530, Ankit Nautiyal wrote:
> Introduce for_each_joiner_candidate(), intel_dp_pick_joiner_candidate() and
> intel_dp_joiner_candidate_valid() to remove duplicated joiner enumeration
> and validity checks across DP SST and MST paths.
>
> Signed-off-by: Ankit Nautiyal <[email protected]>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 37 ++++++++-------------
> drivers/gpu/drm/i915/display/intel_dp.h | 31 +++++++++++++++++
> drivers/gpu/drm/i915/display/intel_dp_mst.c | 37 ++++++++-------------
> 3 files changed, 59 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index c1ff92367808..9eba8f90bc90 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -1529,23 +1529,19 @@ intel_dp_mode_valid(struct drm_connector *_connector,
> * Because of this dependency cycle, the only correct approach is to
> iterate
> * over candidate pipe counts and evaluate each combination.
> */
> - for (num_pipes = 0; num_pipes < I915_MAX_PIPES; num_pipes++) {
> + for_each_joiner_candidate(num_pipes) {
> int dsc_slice_count = 0;
>
> status = MODE_CLOCK_HIGH;
>
> - if (num_pipes == 0) {
> - if (!connector->force_joined_pipes)
> - continue;
> - num_joined_pipes = connector->force_joined_pipes;
> - } else {
> - num_joined_pipes = num_pipes;
> - }
> -
> - if (!intel_dp_can_join(display, num_joined_pipes))
> + if (!intel_dp_pick_joiner_candidate(num_pipes,
> +
> connector->force_joined_pipes,
> + &num_joined_pipes))
> continue;
>
> - if (mode->hdisplay > num_joined_pipes *
> intel_dp_max_hdisplay_per_pipe(display))
> + if (!intel_dp_joiner_candidate_valid(display,
> + mode->hdisplay,
> + num_joined_pipes))
> continue;
By not allowing to fallback from a forced joined-pipe to a non-forced
one as mentioned earlier (and so you'd iterate num_pipes = 1 ..
I915_MAX_PIPES - 1) you could fold all the above into a
for_each_joiner_candidate(connector, mode, num_pipes) helper and with
that yes, the iterator would make sense simplifying things a lot.
>
> status = intel_pfit_mode_valid(display, mode, output_format,
> num_joined_pipes);
> @@ -2938,20 +2934,15 @@ intel_dp_compute_link_config(struct intel_encoder
> *encoder,
> !intel_dp_supports_fec(intel_dp, connector, crtc_state))
> return -EINVAL;
>
> - for (num_pipes = 0; num_pipes < I915_MAX_PIPES; num_pipes++) {
> - if (num_pipes == 0) {
> - if (!connector->force_joined_pipes)
> - continue;
> - num_joined_pipes = connector->force_joined_pipes;
> - } else {
> - num_joined_pipes = num_pipes;
> - }
> -
> - if (!intel_dp_can_join(display, num_joined_pipes))
> + for_each_joiner_candidate(num_pipes) {
> + if (!intel_dp_pick_joiner_candidate(num_pipes,
> +
> connector->force_joined_pipes,
> + &num_joined_pipes))
> continue;
>
> - if (adjusted_mode->hdisplay >
> - num_joined_pipes * intel_dp_max_hdisplay_per_pipe(display))
> + if (!intel_dp_joiner_candidate_valid(display,
> + adjusted_mode->hdisplay,
> + num_joined_pipes))
> continue;
>
> /*
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.h
> b/drivers/gpu/drm/i915/display/intel_dp.h
> index beef480b7672..111a5d4b3992 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
> @@ -234,4 +234,35 @@ bool intel_dp_dotclk_valid(struct intel_display *display,
> int dsc_slice_count,
> int num_joined_pipes);
>
> +#define for_each_joiner_candidate(__num_pipes) \
> + for ((__num_pipes) = 0; (__num_pipes) < (I915_MAX_PIPES);
> (__num_pipes)++)
> +
> +static inline bool intel_dp_pick_joiner_candidate(int num_pipes,
> + int force_joined_pipes,
> + int *num_joined_pipes)
> +{
> + if (num_pipes == 0) {
> + if (!force_joined_pipes)
> + return false;
> + *num_joined_pipes = force_joined_pipes;
> + } else {
> + *num_joined_pipes = num_pipes;
> + }
> +
> + return true;
> +}
> +
> +static inline bool intel_dp_joiner_candidate_valid(struct intel_display
> *display,
> + int hdisplay,
> + int num_joined_pipes)
> +{
> + if (!intel_dp_can_join(display, num_joined_pipes))
> + return false;
> +
> + if (hdisplay > num_joined_pipes *
> intel_dp_max_hdisplay_per_pipe(display))
> + return false;
> +
> + return true;
> +}
> +
> #endif /* __INTEL_DP_H__ */
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index bdf2f09fa03e..005efcb5d2bf 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -701,24 +701,19 @@ static int mst_stream_compute_config(struct
> intel_encoder *encoder,
> pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
> pipe_config->has_pch_encoder = false;
>
> - for (num_pipes = 0; num_pipes < I915_MAX_PIPES; num_pipes++) {
> + for_each_joiner_candidate(num_pipes) {
> int dsc_slice_count = 0;
>
> ret = -EINVAL;
>
> - if (num_pipes == 0) {
> - if (!connector->force_joined_pipes)
> - continue;
> - num_joined_pipes = connector->force_joined_pipes;
> - } else {
> - num_joined_pipes = num_pipes;
> - }
> -
> - if (!intel_dp_can_join(display, num_joined_pipes))
> + if (!intel_dp_pick_joiner_candidate(num_pipes,
> +
> connector->force_joined_pipes,
> + &num_joined_pipes))
> continue;
>
> - if (adjusted_mode->hdisplay >
> - num_joined_pipes * intel_dp_max_hdisplay_per_pipe(display))
> + if (!intel_dp_joiner_candidate_valid(display,
> + adjusted_mode->hdisplay,
> + num_joined_pipes))
> continue;
>
> if (num_joined_pipes > 1)
> @@ -1535,23 +1530,19 @@ mst_connector_mode_valid_ctx(struct drm_connector
> *_connector,
> return 0;
> }
>
> - for (num_pipes = 0; num_pipes < I915_MAX_PIPES; num_pipes++) {
> + for_each_joiner_candidate(num_pipes) {
> int dsc_slice_count = 0;
>
> *status = MODE_CLOCK_HIGH;
>
> - if (num_pipes == 0) {
> - if (!connector->force_joined_pipes)
> - continue;
> - num_joined_pipes = connector->force_joined_pipes;
> - } else {
> - num_joined_pipes = num_pipes;
> - }
> -
> - if (!intel_dp_can_join(display, num_joined_pipes))
> + if (!intel_dp_pick_joiner_candidate(num_pipes,
> +
> connector->force_joined_pipes,
> + &num_joined_pipes))
> continue;
>
> - if (mode->hdisplay > num_joined_pipes *
> intel_dp_max_hdisplay_per_pipe(display))
> + if (!intel_dp_joiner_candidate_valid(display,
> + mode->hdisplay,
> + num_joined_pipes))
> continue;
>
> if (intel_dp_has_dsc(connector) &&
> --
> 2.45.2
>
