[Intel-gfx] [PATCH 1/2] drm/i915: Allow preservation of watermarks.

[Maarten Lankhorst]

Op 02-03-16 om 12:17 schreef Ville Syrjälä:
> On Tue, Mar 01, 2016 at 11:07:21AM +0100, Maarten Lankhorst wrote:
>> As Paulo has noted we can help bisectability by separating computing
>> watermarks on a noop in 2 separate commits.
>>
>> This patch no longer clears the crtc watermark state, but recalculates
>> it completely. Regardless whether a level is used the full values for
>> each level are calculated. If a level is invalid wm[level].enable is
>> unset.
>>
>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>> ---
>>  drivers/gpu/drm/i915/intel_pm.c | 22 ++++++++++++----------
>>  1 file changed, 12 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>> index d33de954a2e4..1b8ba777d2b3 100644
>> --- a/drivers/gpu/drm/i915/intel_pm.c
>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>> @@ -2300,7 +2300,7 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
>>  	struct intel_plane_state *pristate = NULL;
>>  	struct intel_plane_state *sprstate = NULL;
>>  	struct intel_plane_state *curstate = NULL;
>> -	int level, max_level = ilk_wm_max_level(dev);
>> +	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>  	struct ilk_wm_maximums max;
>>  
>>  	cstate = intel_atomic_get_crtc_state(state, intel_crtc);
>> @@ -2308,7 +2308,6 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
>>  		return PTR_ERR(cstate);
>>  
>>  	pipe_wm = &cstate->wm.optimal.ilk;
>> -	memset(pipe_wm, 0, sizeof(*pipe_wm));
>>  
>>  	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>>  		ps = drm_atomic_get_plane_state(state,
>> @@ -2330,13 +2329,15 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
>>  		(drm_rect_width(&sprstate->dst) != drm_rect_width(&sprstate->src) >> 16 ||
>>  		drm_rect_height(&sprstate->dst) != drm_rect_height(&sprstate->src) >> 16);
>>  
>> +	usable_level = max_level;
>> +
>>  	/* ILK/SNB: LP2+ watermarks only w/o sprites */
>>  	if (INTEL_INFO(dev)->gen <= 6 && sprstate->visible)
>> -		max_level = 1;
>> +		usable_level = 1;
>>  
>>  	/* ILK/SNB/IVB: LP1+ watermarks only w/o scaling */
>>  	if (pipe_wm->sprites_scaled)
>> -		max_level = 0;
>> +		usable_level = 0;
>>  
>>  	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>  			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>> @@ -2350,20 +2351,21 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>  
>>  	for (level = 1; level <= max_level; level++) {
>> -		struct intel_wm_level wm = {};
>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>  
>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>> -				     pristate, sprstate, curstate, &wm);
>> +				     pristate, sprstate, curstate, wm);
>>  
>>  		/*
>>  		 * Disable any watermark level that exceeds the
>>  		 * register maximums since such watermarks are
>>  		 * always invalid.
>>  		 */
>> -		if (!ilk_validate_wm_level(level, &max, &wm))
>> -			break;
>> -
>> -		pipe_wm->wm[level] = wm;
>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>> +			usable_level = level;
>> +			wm->enable = false;
>> +		} else if (level > usable_level)
>> +			wm->enable = false;
> That seems to be the wrong way around. I don't think there's
> any point in calling ilk_validate_wm_level() if the level
> already exceeds the max.
>
Indeed! Will fix.