[Intel-gfx] [PATCH 1/2] drm/i915/ddi: Get AUX power domain for DP main link too
Imre Deak
imre.deak at intel.com
Thu Jun 21 18:57:06 UTC 2018
On Thu, Jun 21, 2018 at 11:54:55AM -0700, Manasi Navare wrote:
> On Thu, Jun 21, 2018 at 09:18:55PM +0300, Imre Deak wrote:
> > On Thu, Jun 21, 2018 at 08:37:15PM +0300, Ville Syrjälä wrote:
> > > On Thu, Jun 21, 2018 at 06:58:29PM +0300, Imre Deak wrote:
> > > > So far we got an AUX power domain reference only for the duration of DP
> > > > AUX transfers. However, the followings suggest that we also need these
> > > > for main link functionality:
> > > > - The specification doesn't state whether it's needed or not for main
> > > > link functionality, but suggests that these power wells need to be
> > > > enabled already during display core initialization (Sequences to
> > > > Initialize Display).
> > > > - For PSR we need to keep the AUX power well enabled.
> > > > - On ICL combo PHY ports (non-TC) the AUX power well is needed for
> > > > link training too: while the port is enabled with a DP link training
> > > > test pattern trying to toggle the AUX power well will time out.
> > > > - On ICL MG PHY ports (TC) the AUX power well is needed also for main
> > > > link functionality (both in DP and HDMI modes).
> > > > - Windows enables these power wells both for main and AUX lane
> > > > functionality.
> > > >
> > > > Based on the above take an AUX power reference for main link
> > > > functionality too. This makes a difference only on GEN10+ (GLK+)
> > > > platforms, where we have separate port specific AUX power well
>
> Currently I get AUX timeouts and unable to start link training on DP
> without disable_power_well=0 option set. I think the reason was that
> we were not getting the power domain for the AUX. So hopefully this
> patch should fix it.
Yes, that's because during link training - where the port is enabled
with a training pattern set - we can't enable the AUX power well, it'll
time out. B/c of that AUX transfers will time out too. After disabling
the training pattern and enabling the port for real video signals, AUX
enabling starts to work again..
--Imre
>
> Manasi
>
> > > >
> > > > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > > > Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > > > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > > > ---
> > > > drivers/gpu/drm/i915/intel_ddi.c | 33 +++++++++++++++++++++++++++++----
> > > > drivers/gpu/drm/i915/intel_display.c | 12 +++++++++++-
> > > > drivers/gpu/drm/i915/intel_drv.h | 3 ++-
> > > > 3 files changed, 42 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> > > > index 044fe1fb9872..b09cb6969bbb 100644
> > > > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > > > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > > > @@ -1983,15 +1983,36 @@ bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
> > > > return ret;
> > > > }
> > > >
> > > > -static u64 intel_ddi_get_power_domains(struct intel_encoder *encoder)
> > > > +static u64 intel_ddi_get_power_domains(struct intel_encoder *encoder,
> > > > + struct intel_crtc_state *crtc_state)
> > > > {
> > > > struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base);
> > > > enum pipe pipe;
> > > > + u64 domains;
> > > >
> > > > - if (intel_ddi_get_hw_state(encoder, &pipe))
> > > > - return BIT_ULL(dig_port->ddi_io_power_domain);
> > > > + if (!intel_ddi_get_hw_state(encoder, &pipe))
> > > > + return 0;
> > > >
> > > > - return 0;
> > > > + domains = BIT_ULL(dig_port->ddi_io_power_domain);
> > > > + if (!crtc_state)
> > > > + return domains;
> > > > +
> > > > + /*
> > > > + * TODO: Add support for MST encoders. Atm, the following should never
> > > > + * happen since this function will be called only for the primary
> > > > + * encoder which doesn't have its own pipe/crtc_state.
> > > > + */
> > > > + if (WARN_ON(intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST)))
> > > > + return domains;
> > > > +
> > > > + /* AUX power is only needed for (e)DP mode, not for HDMI. */
> > > > + if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI)) {
> > > > + struct intel_dp *intel_dp = &dig_port->dp;
> > > > +
> > > > + domains |= BIT_ULL(intel_dp->aux_power_domain);
> > > > + }
> > > > +
> > > > + return domains;
> > > > }
> > > >
> > > > void intel_ddi_enable_pipe_clock(const struct intel_crtc_state *crtc_state)
> > > > @@ -2631,6 +2652,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
> > > >
> > > > WARN_ON(is_mst && (port == PORT_A || port == PORT_E));
> > > >
> > > > + intel_display_power_get(dev_priv, intel_dp->aux_power_domain);
> > > > +
> > > > intel_dp_set_link_params(intel_dp, crtc_state->port_clock,
> > > > crtc_state->lane_count, is_mst);
> > > >
> > > > @@ -2775,6 +2798,8 @@ static void intel_ddi_post_disable_dp(struct intel_encoder *encoder,
> > > > intel_display_power_put(dev_priv, dig_port->ddi_io_power_domain);
> > > >
> > > > intel_ddi_clk_disable(encoder);
> > > > +
> > > > + intel_display_power_put(dev_priv, intel_dp->aux_power_domain);
> > > > }
> > > >
> > > > static void intel_ddi_post_disable_hdmi(struct intel_encoder *encoder,
> > > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > > > index 2c8fef3ede54..d9fefcec4b1a 100644
> > > > --- a/drivers/gpu/drm/i915/intel_display.c
> > > > +++ b/drivers/gpu/drm/i915/intel_display.c
> > > > @@ -15676,11 +15676,21 @@ get_encoder_power_domains(struct drm_i915_private *dev_priv)
> > > > for_each_intel_encoder(&dev_priv->drm, encoder) {
> > > > u64 get_domains;
> > > > enum intel_display_power_domain domain;
> > > > + struct intel_crtc_state *crtc_state;
> > > >
> > > > if (!encoder->get_power_domains)
> > > > continue;
> > > >
> > > > - get_domains = encoder->get_power_domains(encoder);
> > > > + /*
> > > > + * In case of a dangling encoder without a crtc we still need
> > > > + * to get power domain refs. Such encoders will be disabled
> > > > + * dropping these references.
> > > > + */
> > > > + crtc_state = encoder->base.crtc ?
> > > > + to_intel_crtc_state(encoder->base.crtc->state) :
> > > > + NULL;
> > >
> > > Actually I think we can just drop this NULL crtc state case. If the
> > > encoder is active it will have a crtc assigned, and only then do we
> > > actually shut it down if the connector/crtc is not active. So if we we
> > > ever did get into a situation where we didn't have the crtc we'd
> > > leak the power references. Also we need the crtc state to shut down
> > > the encoder.
> >
> > Err, thanks for catching that. Confused myself reading
> > intel_sanitize_encoder(), thinking that we'll disable there encoders
> > without a crtc, but that's not the case as you pointed out. Since
> > encoder->base.crtc can be NULL for MST I will still keep the above and
> > rely on intel_ddi_get_hw_state() to skip taking power refs for that
> > case. Will update the comment accrodingly.
> >
> > > The entire sanitize_encoder() thing is a bit wonky. In case we have an
> > > active encoder without a connector it won't actually do anything. I
> > > suppose that could at least happen with sdvo. With ddi it would required
> > > the port to be enabled with the wrong mode which I suppose is a
> > > slightly less realistic option.
> > >
> > > Another case when we wouldn't do anything is if the port is enabled
> > > without any transcoder having selected it. That could happen with
> > > CPT/PPT DP or DDI. Other port types have the pipe select bits on the
> > > port so it's not possible to get into that situation.
> > >
> > > Since we don't seem to have any mysterious bug reports about ports being
> > > wonky maybe these things just don't happen in practice. Or everything
> > > just happens to work out by accient even if don't shut things down
> > > cleanly.
> > >
> > > > +
> > > > + get_domains = encoder->get_power_domains(encoder, crtc_state);
> > > > for_each_power_domain(domain, get_domains)
> > > > intel_display_power_get(dev_priv, domain);
> > > > }
> > > > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > > > index 0c3ac0eafde0..7174429d930a 100644
> > > > --- a/drivers/gpu/drm/i915/intel_drv.h
> > > > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > > > @@ -254,7 +254,8 @@ struct intel_encoder {
> > > > struct intel_crtc_state *pipe_config);
> > > > /* Returns a mask of power domains that need to be referenced as part
> > > > * of the hardware state readout code. */
> > > > - u64 (*get_power_domains)(struct intel_encoder *encoder);
> > > > + u64 (*get_power_domains)(struct intel_encoder *encoder,
> > > > + struct intel_crtc_state *crtc_state);
> > > > /*
> > > > * Called during system suspend after all pending requests for the
> > > > * encoder are flushed (for example for DP AUX transactions) and
> > > > --
> > > > 2.13.2
> > >
> > > --
> > > Ville Syrjälä
> > > Intel
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
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