[Intel-gfx] [PATCH 1/2] drm/i915: Enable DDI IO power domains in the DP MST path

[Imre Deak]

On Tue, Feb 28, 2017 at 09:21:12AM +0200, Ander Conselvan de Oliveira wrote:
> 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>

Reviewed-by: Imre Deak <imre.deak 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
>