From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Vetter <daniel@ffwll.ch>
Subject: Re: [PATCH 2/5] drm/i915/bdw: Implement a basic PM
 interrupt handler
Date: Fri, 16 May 2014 11:09:35 +0200
Message-ID: <20140516090935.GE8790@phenom.ffwll.local>
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To: "O'Rourke, Tom" <Tom.O'Rourke@intel.com>
Cc: "intel-gfx@lists.freedesktop.org" <intel-gfx@lists.freedesktop.org>, "Widawsky, Benjamin" <benjamin.widawsky@intel.com>
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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