[Intel-gfx] [PATCH v2 1/8] drm/i915: Enable DDI IO power domains in the DP MST path

[Ander Conselvan de Oliveira]

Commit 62b695662a24 ("drm/i915: Only enable DDI IO power domains after
enabling DPLL") changed how the DDI IO power domains get enabled, but
neglected the need to enable those domains when enabling a DP connector
with MST enabled, leading to

    Kernel panic - not syncing: Timeout: Not all CPUs entered broadcast exception handler

Fixes: 62b695662a24 ("drm/i915: Only enable DDI IO power domains after enabling DPLL")
Cc: David Weinehall <david.weinehall at linux.intel.com>
Cc: Imre Deak <imre.deak at intel.com>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira at intel.com>
Cc: David Weinehall <david.weinehall at linux.intel.com>
Cc: Daniel Vetter <daniel.vetter at intel.com>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: intel-gfx at lists.freedesktop.org
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Reported-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira at intel.com>
---
 drivers/gpu/drm/i915/intel_dp_mst.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index d94fd4b..a8334e1 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -163,6 +163,9 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
 		intel_ddi_clk_select(&intel_dig_port->base,
 				     pipe_config->shared_dpll);
 
+		intel_display_power_get(dev_priv,
+					intel_dig_port->ddi_io_power_domain);
+
 		intel_prepare_dp_ddi_buffers(&intel_dig_port->base);
 		intel_dp_set_link_params(intel_dp,
 					 pipe_config->port_clock,
-- 
2.9.3