Hi Mika, On Mon, Dec 21, 2015 at 01:39:15PM +0200, Mika Kahola wrote: > Check if no AUX transactions are required on DP link training. > If this bit is set, we can reuse the known good drive current > and pre-emphasis level from the last "full" link training. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91393 > Signed-off-by: Mika Kahola <mika.kahola@xxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_dp.c | 2 +- > drivers/gpu/drm/i915/intel_dp_link_training.c | 19 +++++++++++++++++++ > drivers/gpu/drm/i915/intel_drv.h | 1 + > 3 files changed, 21 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index 6b36d82..3137187 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -3852,7 +3852,7 @@ intel_dp_link_down(struct intel_dp *intel_dp) > intel_dp->DP = DP; > } > > -static bool > +bool > intel_dp_get_dpcd(struct intel_dp *intel_dp) > { > struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); > diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c > index 59d59be..5fb3f97 100644 > --- a/drivers/gpu/drm/i915/intel_dp_link_training.c > +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c > @@ -85,6 +85,25 @@ static bool > intel_dp_reset_link_train(struct intel_dp *intel_dp, > uint8_t dp_train_pat) > { > + bool has_dpcd; > + bool no_aux_handshake = false; > + > + has_dpcd = intel_dp_get_dpcd(intel_dp); > + > + /* > + * Source device can try to use drive current and pre-emphasis > + * parameters computed by the last "full" link training if the > + * DP_NO_AUX_HANDSHAKE_LINK_TRAINING bit is set to 1. > + */ > + if (has_dpcd) { > + if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11) { > + no_aux_handshake = (intel_dp->dpcd[DP_MAX_DOWNSPREAD] & > + DP_NO_AUX_HANDSHAKE_LINK_TRAINING); > + } > + } > + > + intel_dp->train_set_valid &= no_aux_handshake; > + If Thierry Reding's patches get merged (posted to dri-devel@ on Dec 14 with <1450097764-30063-1-git-send-email-thierry.reding@xxxxxxxxx>), you could just use if (has_dpcd && drm_dp_fast_training_cap(intel_dp->dpcd)) intel_dp->train_set_valid &= true; Also, if the patches get merged, the no_aux_handshake attribute in dev_priv can be dropped (set in intel_edp_init_connector() but never read). Best regards, Lukas > DRM_DEBUG_KMS("link training optimization: %s\n", > intel_dp->train_set_valid ? "true" : "false"); > > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > index d523ebb..c36a70c 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -1239,6 +1239,7 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc); > bool intel_dp_compute_config(struct intel_encoder *encoder, > struct intel_crtc_state *pipe_config); > bool intel_dp_is_edp(struct drm_device *dev, enum port port); > +bool intel_dp_get_dpcd(struct intel_dp *intel_dp); > enum irqreturn intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, > bool long_hpd); > void intel_edp_backlight_on(struct intel_dp *intel_dp); > -- > 1.9.1 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
