[Intel-gfx] [PATCH v2 9/9] drm/i915: Leave interrupts enabled while disabling crtcs during suspend

[Daniel Vetter]

On Mon, May 26, 2014 at 02:46:32PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> The new watermaek update mechanism requires interrupts to work
> correctly. Because of this we need interrupts while disabling crtcs
> during suspend. So move the irq disable to happen a bit later.
> 
> This also avoid clobbering the vblank.last count in case the
> vblank interrupt was already disabled earlier by the timer.
> In that case drm_vblank_off() will need .last to be correct so
> that it can update the user visible vblank counter value
> approapriately.
> 
> v2: Note vblank counter in commit message
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

First round of this patch had a question from me whether we have
sufficient amounts of WARN_ON(! or !!dev->irqs_enabled) sprinkled all over
the place ... Do we have that?

I'm specifically thinking of places where we cancel some work/time
lauchned by interrupts and must have the guarantee in place that it can't
rearm.

Otoh we have places where we absolutely want interrupts to still work,
e.g. in gpu_idle.

Sprinkling some modeset amounts of WARNS in a follow-up would make me
really happy.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_drv.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 4619c9e..21554a0 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -524,7 +524,6 @@ static int i915_drm_freeze(struct drm_device *dev)
>  			return error;
>  		}
>  
> -		drm_irq_uninstall(dev);
>  		dev_priv->enable_hotplug_processing = false;
>  
>  		intel_disable_gt_powersave(dev);
> @@ -541,6 +540,8 @@ static int i915_drm_freeze(struct drm_device *dev)
>  		}
>  		mutex_unlock(&dev->mode_config.mutex);
>  
> +		drm_irq_uninstall(dev);
> +
>  		intel_modeset_suspend_hw(dev);
>  	}
>  
> -- 
> 1.8.5.5
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch