Re: [RFCv2 16/19] drm/i915: Sanity check all registers for matching fw domains

From: Chris Wilson <chris@chris-wilson.co.uk>
To: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Intel Graphics Development <intel-gfx@lists.freedesktop.org>
Subject: Re: [RFCv2 16/19] drm/i915: Sanity check all registers for matching fw domains
Date: Wed, 11 Jan 2017 18:39:08 +0000	[thread overview]
Message-ID: <20170111183908.GF16278@nuc-i3427.alporthouse.com> (raw)
In-Reply-To: <CAM0jSHPhtHYUvNS6gmk9p7hJmq8-Jmg96knNny+jir4jtxS_AA@mail.gmail.com>

On Wed, Jan 11, 2017 at 06:25:59PM +0000, Matthew Auld wrote:
> On 20 December 2016 at 13:08, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > +       for_each_set_bit(offset, valid, FW_RANGE) {
> > +               i915_reg_t reg = { offset };
> > +
> > +               intel_uncore_forcewake_reset(dev_priv, false);
> > +               check_for_unclaimed_mmio(dev_priv);
> hmm, what do we need this for ?

It clears the debug register before every test - so that we know the
only thing the debug register is complaining about is the I915_READ()
sandwiched in between. The reset is there to ensure that the fw is
turned off and the timer disabled, so that we have a vanilla state
every time with the powerwell off. Hopefully.

> > +
> > +               (void)I915_READ(reg);
> > +               if (check_for_unclaimed_mmio(dev_priv)) {

-- 
Chris Wilson, Intel Open Source Technology Centre
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