[Intel-gfx] [PATCH v2 4/4] drm/i915: Calculate vlv/chv intermediate watermarks correctly, v2.

[Maarten Lankhorst]

Op 03-05-17 om 18:07 schreef Ville Syrjälä:
> On Wed, May 03, 2017 at 05:53:34PM +0200, Maarten Lankhorst wrote:
>> Op 03-05-17 om 16:11 schreef Ville Syrjälä:
>>> On Wed, May 03, 2017 at 04:06:37PM +0200, Maarten Lankhorst wrote:
>>>> Op 03-05-17 om 15:45 schreef Ville Syrjälä:
>>>>> On Mon, May 01, 2017 at 03:34:34PM +0200, Maarten Lankhorst wrote:
>>>>>> The watermarks it should calculate against are the old optimal watermarks.
>>>>>> The currently active crtc watermarks are pure fiction, and are invalid in
>>>>>> case of a nonblocking modeset, page flip enabling/disabling planes or any
>>>>>> other reason.
>>>>>>
>>>>>> When the crtc is disabled or during a modeset the intermediate watermarks
>>>>>> don't need to be programmed separately, and could be directly assigned
>>>>>> to the optimal watermarks.
>>>>>>
>>>>>> Also rename crtc_state to new_crtc_state, to distinguish it from the old state.
>>>>>>
>>>>>> Changes since v1:
>>>>>> - Use intel_atomic_get_old_crtc_state. (ville)
>>>>>>
>>>>>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>>>>>> ---
>>>>>>  drivers/gpu/drm/i915/intel_pm.c | 20 ++++++++++++++------
>>>>>>  1 file changed, 14 insertions(+), 6 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>>>>> index 0f344b1fff45..a09396ee1f3d 100644
>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>>>>> @@ -1458,16 +1458,24 @@ static void vlv_atomic_update_fifo(struct intel_atomic_state *state,
>>>>>>  
>>>>>>  static int vlv_compute_intermediate_wm(struct drm_device *dev,
>>>>>>  				       struct intel_crtc *crtc,
>>>>>> -				       struct intel_crtc_state *crtc_state)
>>>>>> +				       struct intel_crtc_state *new_crtc_state)
>>>>>>  {
>>>>>> -	struct vlv_wm_state *intermediate = &crtc_state->wm.vlv.intermediate;
>>>>>> -	const struct vlv_wm_state *optimal = &crtc_state->wm.vlv.optimal;
>>>>>> -	const struct vlv_wm_state *active = &crtc->wm.active.vlv;
>>>>>> +	struct vlv_wm_state *intermediate = &new_crtc_state->wm.vlv.intermediate;
>>>>>> +	const struct vlv_wm_state *optimal = &new_crtc_state->wm.vlv.optimal;
>>>>>> +	const struct intel_crtc_state *old_crtc_state =
>>>>>> +		intel_atomic_get_old_crtc_state(new_crtc_state->base.state, crtc);
>>>>>> +	const struct vlv_wm_state *active = &old_crtc_state->wm.vlv.optimal;
>>>>>>  	int level;
>>>>>>  
>>>>>> +	if (!new_crtc_state->base.active || drm_atomic_crtc_needs_modeset(&new_crtc_state->base)) {
>>>>>> +		*intermediate = *optimal;
>>>>>> +
>>>>>> +		return 0;
>>>>>> +	}
>>>>>> +
>>>>>>  	intermediate->num_levels = min(optimal->num_levels, active->num_levels);
>>>>>>  	intermediate->cxsr = optimal->cxsr && active->cxsr &&
>>>>>> -		!crtc_state->disable_cxsr;
>>>>>> +		!new_crtc_state->disable_cxsr;
>>>>> We need to consider disable_cxsr even in the modeset case.
>>>> Why is this? crtc_state->disable_cxsr is set if any plane is part of the crtc during modeset, so it's disabled during modeset already.
>>> It's set if any plane is enabling/disabling, which should be quite
>>> typical during a modeset.
>> Yeah but .initial_watermarks is called during crtc_enable, so cxsr will get enabled anyway.
> Which is not what we want. CxSR must stay off until the planes have been
> enabled.
>
In that case why is it enabled in .initial_watermarks at all? It should be in optimize_watermarks then..