Re: [PATCH 14/14] drm/i915: simplify rps interrupt enabling/disabling sequence

[Daniel Vetter <daniel@ffwll.ch>]

On Thu, Jul 04, 2013 at 11:35:34PM +0200, Daniel Vetter wrote:
> At the moment we have the following interrupt enabling sequence:
> 1. irq preinstall hook
> 2. enabling the interrupt handler and calling irq postinstall hook
> 3. enable rps interrupts from the async work
> 
> And the folliwing disable sequence:
> 1. disabling the interrupt handler and calling the uninstall hook
> 2. disabling the rps interrupt
> 
> Since the postinstall hook now always sets up PMIIR, PMIER and PMIMR
> to known-good states there no way for an interrupt to sneak in in the
> enable sequence, so we can reinstate the WARN lost in
> 
> commit eda63ffb906c2fb3b609a0e87aeb63c0f25b9e6b
> Author: Ben Widawsky <ben@bwidawsk.net>
> Date:   Tue May 28 19:22:26 2013 -0700
> 
>     drm/i915: Add PM regs to pre/post install
> 
> Note that there's some room for future cleanups since most of the
> interrupt register clearing in the disable function is rather
> redundant. But that's better done in follow-up patches, if at all.
> 
> Cc: Ben Widawsky <ben@bwidawsk.net>
> Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Ok, final 4 patches from this series are now merged. Thanks everyone for
the review.
-Daniel

> ---
>  drivers/gpu/drm/i915/intel_pm.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 787a528..bc5aae0 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3193,9 +3193,7 @@ static void gen6_enable_rps_interrupts(struct drm_device *dev)
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
>  	spin_lock_irq(&dev_priv->irq_lock);
> -	/* FIXME: Our interrupt enabling sequence is bonghits.
> -	 * dev_priv->rps.pm_iir really should be 0 here. */
> -	dev_priv->rps.pm_iir = 0;
> +	WARN_ON(dev_priv->rps.pm_iir);
>  	I915_WRITE(GEN6_PMIMR, I915_READ(GEN6_PMIMR) & ~GEN6_PM_RPS_EVENTS);
>  	I915_WRITE(GEN6_PMIIR, GEN6_PM_RPS_EVENTS);
>  	spin_unlock_irq(&dev_priv->irq_lock);
> -- 
> 1.8.1.4
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch