Re: [PATCH 2/5] drm/i915/bdw: Implement a basic PM interrupt handler

Daniel Vetter
2014-05-16T09:09:40Z

On Fri, May 16, 2014 at 01:38:18AM +0000, O'Rourke, Tom wrote:
> >+static void gen8_disable_rps_interrupts(struct drm_device *dev) {
> >+ struct drm_i915_private *dev_priv = dev->dev_private;
> >+
> >+ I915_WRITE(GEN6_PMINTRMSK, 0xffffffff);
>
> [TOR:] Please note that for Broadwell, bit 31 in GEN6_PMINTRMSK is not an interrupt disable bit.
> In "drm/i915: Enable PM Interrupts target via Display Interface." this bit is defined as:
> +#define GEN8_PMINTR_REDIRECT_TO_NON_DISP (1<<31)
>
> Writing this bit here could have unintended consequences.

Hm, we seem to unconditionally set this bit on gen8 anyway. Still harmful?
Mika, Ville?
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch