On Fri, 27 Oct 2017, Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > DP dongles may signal downstream HPD via short HPD pulses. Setting the > sink to DPMS off apparently kills the downstream HPD (at least on my > DP->VGA dongle), so skip the DPMS off for such dongles when we turn > off the port. > > v2: Deal with DDI as well by moving the check into > intel_dp_sink_dpms() (Dhinakaran) > > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> > Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx> > Cc: Imre Deak <imre.deak@xxxxxxxxx> > Cc: Pablo <pablodebiase@xxxxxxxxxxxxx> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103472 > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99114 > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_dp.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index aa75f55eeb61..59169a4dc9d3 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -2505,6 +2505,21 @@ static void ironlake_edp_pll_off(struct intel_dp *intel_dp) > udelay(200); > } > > +static bool downstream_hpd_needs_d0(struct intel_dp *intel_dp) > +{ > + /* > + * DPCD 1.2+ should support BRANCH_DEVICE_CTRL, and thus > + * be capable of signalling downstream hpd with a long pulse. > + * Whether or not that means D3 is safe to use is not clear, > + * but let's assume so until proven otherwise. > + * > + * FIXME should really check all downstream ports... > + */ > + return intel_dp->dpcd[DP_DPCD_REV] == 0x11 && > + intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT && > + intel_dp->downstream_ports[0] & DP_DS_PORT_HPD; > +} > + > /* If the sink supports it, try to set the power state appropriately */ > void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode) > { > @@ -2515,6 +2530,9 @@ void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode) > return; > > if (mode != DRM_MODE_DPMS_ON) { > + if (downstream_hpd_needs_d0(intel_dp)) > + return; > + > ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER, > DP_SET_POWER_D3); > } else { -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
