Re: [Intel-gfx] [Intel-xe] [PATCH 1/5] drm/i915: Split display locks init from i915_driver_early_probe()

[Jani Nikula <jani.nikula@intel.com>]

On Mon, 03 Apr 2023, Rodrigo Vivi <rodrigo.vivi@intel.com> wrote:
> On Mon, Apr 03, 2023 at 02:10:26PM -0400, Souza, Jose wrote:
>> On Mon, 2023-04-03 at 13:03 -0400, Rodrigo Vivi wrote:
>> > On Mon, Apr 03, 2023 at 09:46:11AM -0700, José Roberto de Souza wrote:
>> > > No behavior changes here, just adding a function to make clear
>> > > what locks initialized here are display related or not.
>> > > 
>> > > Cc: intel-gfx@lists.freedesktop.org
>> > > Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
>> > > ---
>> > >  drivers/gpu/drm/i915/i915_driver.c | 23 +++++++++++++++--------
>> > >  1 file changed, 15 insertions(+), 8 deletions(-)
>> > > 
>> > > diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
>> > > index 066d79c2069c4..224cb4cb43335 100644
>> > > --- a/drivers/gpu/drm/i915/i915_driver.c
>> > > +++ b/drivers/gpu/drm/i915/i915_driver.c
>> > > @@ -188,6 +188,20 @@ static void sanitize_gpu(struct drm_i915_private *i915)
>> > >  	}
>> > >  }
>> > >  
>> > > +static void
>> > > +i915_driver_display_early_probe(struct drm_i915_private *dev_priv)
>> > > +{
>> > > +	spin_lock_init(&dev_priv->display.fb_tracking.lock);
>> > > +	spin_lock_init(&dev_priv->display.wm.dsparb_lock);
>> > > +	mutex_init(&dev_priv->display.backlight.lock);
>> > > +
>> > > +	mutex_init(&dev_priv->display.audio.mutex);
>> > > +	mutex_init(&dev_priv->display.wm.wm_mutex);
>> > > +	mutex_init(&dev_priv->display.pps.mutex);
>> > > +	mutex_init(&dev_priv->display.hdcp.comp_mutex);
>> > > +	spin_lock_init(&dev_priv->display.dkl.phy_lock);
>> > > +}
>> > > +
>> > 
>> > hmmm... I like that, however Jani had indicated in another series [1]
>> > that he would prefer the wm mutex inside the wm code for instance...
>> > 
>> > So, should we move all of these to their own components instead of this
>> > move?
>> > 
>> > [1] https://patchwork.freedesktop.org/series/115675/
>> > 
>> > I checked and for a few components it is simple to move them to their
>> > own init functions. However for a few we would need to create new init
>> > functions and call them here.
>> > 
>> > Jani, more thoughts?
>> 
>> Forgot to CC you two in the new version: https://patchwork.freedesktop.org/series/116039/
>> 
>> display.wm.dsparb_lock is not used anywhere.
>
> it currently doesn't exist on drm-intel. Not sure how it appeared in drm-xe...
> Probably a !fixup needed on initial display patches.
>
> Please notice that my series on the link I sent earlier re-introduce it with a proper
> usage. Ville had already reviewed the code, but I hold the push because Jani
> asked about a better placement.
>
> What I tried to say earlier here is that this patch is probably not following
> Jani's vision on how to organize the initialization of these many
> locks.

That's right.

Audio init should initialize audio.mutex.

Watermark init should initialize wm.wm_mutex.

PPS init should initialize pps.mutex.

Etc.

Moreover, display.audio should only be accessed by intel_audio.c. Etc.

BR,
Jani.






>
>> Moved display.dkl.phy_lock, will leave the rest to someone to take over.
>> 
>> 
>> > 
>> > >  /**
>> > >   * i915_driver_early_probe - setup state not requiring device access
>> > >   * @dev_priv: device private
>> > > @@ -213,18 +227,11 @@ static int i915_driver_early_probe(struct drm_i915_private *dev_priv)
>> > >  
>> > >  	spin_lock_init(&dev_priv->irq_lock);
>> > >  	spin_lock_init(&dev_priv->gpu_error.lock);
>> > > -	spin_lock_init(&dev_priv->display.fb_tracking.lock);
>> > > -	spin_lock_init(&dev_priv->display.wm.dsparb_lock);
>> > > -	mutex_init(&dev_priv->display.backlight.lock);
>> > >  
>> > >  	mutex_init(&dev_priv->sb_lock);
>> > >  	cpu_latency_qos_add_request(&dev_priv->sb_qos, PM_QOS_DEFAULT_VALUE);
>> > >  
>> > > -	mutex_init(&dev_priv->display.audio.mutex);
>> > > -	mutex_init(&dev_priv->display.wm.wm_mutex);
>> > > -	mutex_init(&dev_priv->display.pps.mutex);
>> > > -	mutex_init(&dev_priv->display.hdcp.comp_mutex);
>> > > -	spin_lock_init(&dev_priv->display.dkl.phy_lock);
>> > > +	i915_driver_display_early_probe(dev_priv);
>> > >  
>> > >  	i915_memcpy_init_early(dev_priv);
>> > >  	intel_runtime_pm_init_early(&dev_priv->runtime_pm);
>> > > -- 
>> > > 2.40.0
>> > > 
>> 

-- 
Jani Nikula, Intel Open Source Graphics Center