[Intel-gfx] [PATCH] drm/i915/mst: Set intel_dp_set_m_n() for MST slaves

[Jani Nikula]

On Mon, 10 Feb 2020, José Roberto de Souza <jose.souza at intel.com> wrote:
> Commit 1c9d2eb24153 ("drm/i915: move intel_dp_set_m_n() to encoder for
> DDI platforms") moved the intel_dp_set_m_n() from hsw_crtc_enable()
> to intel_ddi_pre_enable_dp() but it missed add it to
> intel_mst_pre_enable_dp() causing MST slaves to not work.
>
> Fixes: 1c9d2eb24153 ("drm/i915: move intel_dp_set_m_n() to encoder for DDI platforms")
> Cc: Vandita Kulkarni <vandita.kulkarni at intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>

Damn it, this is the second DP MST thing I missed in the same
series. *facepalm*. The first goof-up was fixed in commit 274959622017
("drm/i915/mst: fix pipe and vblank enable"). We really need more MST in
CI.

Reviewed-by: Jani Nikula <jani.nikula at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_dp_mst.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 9cd59141953d..d7bfa7c350e9 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -480,6 +480,8 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
>  		intel_ddi_enable_pipe_clock(pipe_config);
>  
>  	intel_ddi_set_dp_msa(pipe_config, conn_state);
> +
> +	intel_dp_set_m_n(pipe_config, M1_N1);
>  }
>  
>  static void intel_mst_enable_dp(struct intel_encoder *encoder,

-- 
Jani Nikula, Intel Open Source Graphics Center