From: Ville Syrjälä <ville.syrj...@linux.intel.com> 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.
Cc: David Woodhouse <dw...@infradead.org> Cc: Imre Deak <imre.d...@intel.com> Cc: Pablo <pablodebi...@nanalysis.com> 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.syrj...@linux.intel.com> --- drivers/gpu/drm/i915/intel_dp.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index aa75f55eeb61..6ecc1b532f15 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -2673,6 +2673,21 @@ static void intel_dp_get_config(struct intel_encoder *encoder, } } +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; +} + static void intel_disable_dp(struct intel_encoder *encoder, const struct intel_crtc_state *old_crtc_state, const struct drm_connector_state *old_conn_state) @@ -2686,7 +2701,8 @@ static void intel_disable_dp(struct intel_encoder *encoder, * ensure that we have vdd while we switch off the panel. */ intel_edp_panel_vdd_on(intel_dp); intel_edp_backlight_off(old_conn_state); - intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF); + if (!downstream_hpd_needs_d0(intel_dp)) + intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF); intel_edp_panel_off(intel_dp); } -- 2.13.6 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
