On Fri, May 22, 2026 at 12:36:27AM +0300, Ville Syrjälä wrote:
> On Mon, May 18, 2026 at 02:24:22PM +0300, Imre Deak wrote:
> > Add helpers to defer and handle link params resets instead of
> > open-coding the same. Rename intel_dp_reset_link_params() to
> > intel_dp_reset_link_params_force() to align its name with the new
> > deferred reset helpers.
> >
> > When deferring a reset, return whether a new reset was queued, used by a
> > follow-up change.
> >
> > Signed-off-by: Imre Deak <[email protected]>
> > ---
> > drivers/gpu/drm/i915/display/g4x_dp.c | 2 +-
> > drivers/gpu/drm/i915/display/intel_ddi.c | 2 +-
> > drivers/gpu/drm/i915/display/intel_dp.c | 41 +++++++++++++++----
> > drivers/gpu/drm/i915/display/intel_dp.h | 3 +-
> > .../drm/i915/display/intel_dp_link_training.c | 4 +-
> > 5 files changed, 38 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/g4x_dp.c
> > b/drivers/gpu/drm/i915/display/g4x_dp.c
> > index 5ff1cdf4581a5..c20a97e21419b 100644
> > --- a/drivers/gpu/drm/i915/display/g4x_dp.c
> > +++ b/drivers/gpu/drm/i915/display/g4x_dp.c
> > @@ -1265,7 +1265,7 @@ static void intel_dp_encoder_reset(struct drm_encoder
> > *encoder)
> >
> > intel_dp->DP = intel_de_read(display, intel_dp->output_reg);
> >
> > - intel_dp->reset_link_params = true;
> > + intel_dp_reset_link_params_defer(intel_dp);
> > intel_dp_invalidate_source_oui(intel_dp);
> >
> > if (display->platform.valleyview || display->platform.cherryview)
> > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> > b/drivers/gpu/drm/i915/display/intel_ddi.c
> > index 86520848892e0..77819aaeccb76 100644
> > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > @@ -4664,7 +4664,7 @@ static void intel_ddi_encoder_reset(struct
> > drm_encoder *encoder)
> > struct intel_dp *intel_dp = enc_to_intel_dp(to_intel_encoder(encoder));
> > struct intel_digital_port *dig_port =
> > enc_to_dig_port(to_intel_encoder(encoder));
> >
> > - intel_dp->reset_link_params = true;
> > + intel_dp_reset_link_params_defer(intel_dp);
> > intel_dp_invalidate_source_oui(intel_dp);
> >
> > intel_pps_encoder_reset(intel_dp);
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 1920d2f026665..13163dd085e91 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -3710,7 +3710,11 @@ void intel_dp_set_link_params(struct intel_dp
> > *intel_dp,
> > intel_dp->lane_count = lane_count;
> > }
> >
> > -void intel_dp_reset_link_params(struct intel_dp *intel_dp)
> > +/*
> > + * Reset link params now, preserving any deferred connector
> > + * detect-time reset request.
> > + */
> > +void intel_dp_reset_link_params_force(struct intel_dp *intel_dp)
> > {
> > intel_dp->link.max_lane_count =
> > intel_dp_max_common_lane_count(intel_dp);
> > intel_dp->link.max_rate = intel_dp_max_common_rate(intel_dp);
> > @@ -3720,6 +3724,28 @@ void intel_dp_reset_link_params(struct intel_dp
> > *intel_dp)
> > intel_dp->link.seq_train_failures = 0;
> > }
> >
> > +/*
> > + * Reset link params during the next connector detect.
> > + * Return %true if a new reset was queued.
> > + */
> > +bool intel_dp_reset_link_params_defer(struct intel_dp *intel_dp)
>
> I find the intel_dp_reset_link_params_defer() vs.
> intel_dp_reset_link_params_force() naming rather confusing.
>
> Can't immediately think of a really good name for
> intel_dp_reset_link_params_defer() so maybe it's better to not
> have a function for it at all (ie. just drop this patch)?
The idea was to have an interface to reset the link params directly or
in a deferred way, instead of a direct access of the flag.
The names are not great yes. I could use what Jouni suggested instead,
or if the above argument is not good enough I can also drop this patch.
> Then you at least see that it's just setting the flag. AFAICS you only
> have a single place (in the last patch) that uses this return value
> for anything, so could just do the check+set dance there on the spot.
>
> > +{
> > + bool reset_was_pending = intel_dp->reset_link_params;
> > +
> > + intel_dp->reset_link_params = true;
> > +
> > + return !reset_was_pending;
> > +}
> > +
> > +static void intel_dp_handle_deferred_link_params_reset(struct intel_dp
> > *intel_dp)
> > +{
> > + if (!intel_dp->reset_link_params)
> > + return;
> > +
> > + intel_dp->reset_link_params = false;
> > + intel_dp_reset_link_params_force(intel_dp);
> > +}
> > +
> > /* Enable backlight PWM and backlight PP control. */
> > void intel_edp_backlight_on(const struct intel_crtc_state *crtc_state,
> > const struct drm_connector_state *conn_state)
> > @@ -4066,7 +4092,7 @@ void intel_dp_sync_state(struct intel_encoder
> > *encoder,
> > intel_dp_tunnel_resume(intel_dp, crtc_state, dpcd_updated);
> >
> > if (crtc_state) {
> > - intel_dp_reset_link_params(intel_dp);
> > + intel_dp_reset_link_params_force(intel_dp);
> > intel_dp_set_link_params(intel_dp, crtc_state->port_clock,
> > crtc_state->lane_count);
> > intel_dp->link.active = true;
> > }
> > @@ -6487,10 +6513,7 @@ intel_dp_detect(struct drm_connector *_connector,
> >
> > intel_dp_detect_sdp_caps(intel_dp);
> >
> > - if (intel_dp->reset_link_params) {
> > - intel_dp_reset_link_params(intel_dp);
> > - intel_dp->reset_link_params = false;
> > - }
> > + intel_dp_handle_deferred_link_params_reset(intel_dp);
> >
> > intel_dp_mst_configure(intel_dp);
> >
> > @@ -6944,7 +6967,7 @@ intel_dp_hpd_pulse(struct intel_digital_port
> > *dig_port, bool long_hpd)
> >
> > intel_dp_read_dprx_caps(intel_dp, dpcd);
> >
> > - intel_dp->reset_link_params = true;
> > + intel_dp_reset_link_params_defer(intel_dp);
> > intel_dp_invalidate_source_oui(intel_dp);
> >
> > return IRQ_NONE;
> > @@ -7252,7 +7275,7 @@ intel_dp_init_connector(struct intel_digital_port
> > *dig_port,
> > encoder->base.name))
> > return false;
> >
> > - intel_dp->reset_link_params = true;
> > + intel_dp_reset_link_params_defer(intel_dp);
> >
> > /* Preserve the current hw state. */
> > intel_dp->DP = intel_de_read(display, intel_dp->output_reg);
> > @@ -7317,7 +7340,7 @@ intel_dp_init_connector(struct intel_digital_port
> > *dig_port,
> >
> > intel_dp_set_source_rates(intel_dp);
> > intel_dp_set_common_rates(intel_dp);
> > - intel_dp_reset_link_params(intel_dp);
> > + intel_dp_reset_link_params_force(intel_dp);
> >
> > /* init MST on ports that can support it */
> > intel_dp_mst_encoder_init(dig_port, connector->base.base.id);
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.h
> > b/drivers/gpu/drm/i915/display/intel_dp.h
> > index f41480d247142..7c24d3dbb6983 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.h
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.h
> > @@ -114,7 +114,8 @@ int intel_dp_rate_index(const int *rates, int len, int
> > rate);
> > int intel_dp_link_config_index(struct intel_dp *intel_dp, int link_rate,
> > int lane_count);
> > void intel_dp_link_config_get(struct intel_dp *intel_dp, int idx, int
> > *link_rate, int *lane_count);
> > void intel_dp_update_sink_caps(struct intel_dp *intel_dp);
> > -void intel_dp_reset_link_params(struct intel_dp *intel_dp);
> > +void intel_dp_reset_link_params_force(struct intel_dp *intel_dp);
> > +bool intel_dp_reset_link_params_defer(struct intel_dp *intel_dp);
> >
> > void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,
> > u8 *link_bw, u8 *rate_select);
> > 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 a26094223f780..b7075060e7bd3 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> > @@ -1935,7 +1935,7 @@ static ssize_t i915_dp_force_link_rate_write(struct
> > file *file,
> > if (err)
> > return err;
> >
> > - intel_dp_reset_link_params(intel_dp);
> > + intel_dp_reset_link_params_force(intel_dp);
> > intel_dp->link.force_rate = rate;
> >
> > drm_modeset_unlock(&display->drm->mode_config.connection_mutex);
> > @@ -2037,7 +2037,7 @@ static ssize_t i915_dp_force_lane_count_write(struct
> > file *file,
> > if (err)
> > return err;
> >
> > - intel_dp_reset_link_params(intel_dp);
> > + intel_dp_reset_link_params_force(intel_dp);
> > intel_dp->link.force_lane_count = lane_count;
> >
> > drm_modeset_unlock(&display->drm->mode_config.connection_mutex);
> > --
> > 2.49.1
>
> --
> Ville Syrjälä
> Intel
