Re: [v4,01/14] drm/i915: Fix PIPEDMC disabling for a bigjoiner configuration

[Rudi Heitbaum]

Hi Imre/Dave,

Ref: [v4,01/14] drm/i915: Fix PIPEDMC disabling for a bigjoiner configuration
     [git pull] drm fixes for 6.4-rc4
     drm-fixes-2023-05-26:
     drm fixes for 6.4-rc4

This patch has caused a regression between 6.4-rc3 and 6.4-rc4. Other
tested kernels include 6.3.4 work fine. Dropping the patch allows the decode
playback of media via Kodi. Without dropping the patch - the media
starts and stutters then ceases to play.

There is an additional issue that 6.4-rc4 audio playback is also failing
(where 6.4-rc3 was fine), I have not yet tracked this down.

This is all on:
DMI: Intel(R) Client Systems NUC12WSKi7/NUC12WSBi7, BIOS WSADL357.0087.2023.0306.1931 03/06/2023
12th Gen Intel(R) Core(TM) i7-1260P (family: 0x6, model: 0x9a, stepping: 0x3)
microcode: updated early: 0x429 -> 0x42a, date = 2023-02-14

Regards

Rudi

On Wed, May 10, 2023 at 01:31:18PM +0300, Imre Deak wrote:
> For a bigjoiner configuration display->crtc_disable() will be called
> first for the slave CRTCs and then for the master CRTC. However slave
> CRTCs will be actually disabled only after the master CRTC is disabled
> (from the encoder disable hooks called with the master CRTC state).
> Hence the slave PIPEDMCs can be disabled only after the master CRTC is
> disabled, make this so.
> 
> intel_encoders_post_pll_disable() must be called only for the master
> CRTC, as for the other two encoder disable hooks. While at it fix this
> up as well. This didn't cause a problem, since
> intel_encoders_post_pll_disable() will call the corresponding hook only
> for an encoder/connector connected to the given CRTC, however slave
> CRTCs will have no associated encoder/connector.
> 
> Fixes: 3af2ff0840be ("drm/i915: Enable a PIPEDMC whenever its corresponding pipe is enabled")
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 1d5d42a408035..116fa52290b84 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -1702,9 +1702,17 @@ static void hsw_crtc_disable(struct intel_atomic_state *state,
>  
>  	intel_disable_shared_dpll(old_crtc_state);
>  
> -	intel_encoders_post_pll_disable(state, crtc);
> +	if (!intel_crtc_is_bigjoiner_slave(old_crtc_state)) {
> +		struct intel_crtc *slave_crtc;
> +
> +		intel_encoders_post_pll_disable(state, crtc);
>  
> -	intel_dmc_disable_pipe(i915, crtc->pipe);
> +		intel_dmc_disable_pipe(i915, crtc->pipe);
> +
> +		for_each_intel_crtc_in_pipe_mask(&i915->drm, slave_crtc,
> +						 intel_crtc_bigjoiner_slave_pipes(old_crtc_state))
> +			intel_dmc_disable_pipe(i915, slave_crtc->pipe);
> +	}
>  }
>  
>  static void i9xx_pfit_enable(const struct intel_crtc_state *crtc_state)