DK, please start stable backport commit messages with: commit b1e314462bba76660eec62760bb2e87f28f58866 upstream. Referencing the upstream commit. BR, Jani. On Thu, 29 Mar 2018, Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> wrote: > If bios sets up an MST output and hardware state readout code sees this is > an SST configuration, when disabling the encoder we end up calling > ->post_disable_dp() hook instead of the MST version. Consequently, we write > to the DP_SET_POWER dpcd to set it D3 state. Further along when we try > enable the encoder in MST mode, POWER_UP_PHY transaction fails to power up > the MST hub. This results in continuous link training failures which keep > the system busy delaying boot. We could identify bios MST boot discrepancy > and handle it accordingly but a simple way to solve this is to write to the > DP_SET_POWER dpcd for MST too. > > v2: Rebased on stable/linux-4.15.y and fixed minor conflict. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105470 > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Cc: Jani Nikula <jani.nikula@xxxxxxxxx> > Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Reported-by: Laura Abbott <labbott@xxxxxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> # 4.15+ > Fixes: 5ea2355a100a ("drm/i915/mst: Use MST sideband message transactions for dpms control") > Tested-by: Laura Abbott <labbott@xxxxxxxxxx> > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> > Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> > Link: https://patchwork.freedesktop.org/patch/msgid/20180314054825.1718-1-dhinakaran.pandiyan@xxxxxxxxx > (cherry picked from commit ad260ab32a4d94fa974f58262f8000472d34fd5b) > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_ddi.c | 12 ++---------- > 1 file changed, 2 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c > index 58a3755544b2..38e53d6b8127 100644 > --- a/drivers/gpu/drm/i915/intel_ddi.c > +++ b/drivers/gpu/drm/i915/intel_ddi.c > @@ -2208,8 +2208,7 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > intel_prepare_dp_ddi_buffers(encoder); > > intel_ddi_init_dp_buf_reg(encoder); > - if (!is_mst) > - intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > + intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > intel_dp_start_link_train(intel_dp); > if (port != PORT_A || INTEL_GEN(dev_priv) >= 9) > intel_dp_stop_link_train(intel_dp); > @@ -2294,19 +2293,12 @@ static void intel_ddi_post_disable_dp(struct intel_encoder *encoder, > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base); > struct intel_dp *intel_dp = &dig_port->dp; > - /* > - * old_crtc_state and old_conn_state are NULL when called from > - * DP_MST. The main connector associated with this port is never > - * bound to a crtc for MST. > - */ > - bool is_mst = !old_crtc_state; > > /* > * Power down sink before disabling the port, otherwise we end > * up getting interrupts from the sink on detecting link loss. > */ > - if (!is_mst) > - intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF); > + intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF); > > intel_disable_ddi_buf(encoder); -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
