From: Damien Lespiau <damien.lespiau@intel.com>
To: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH 2/2] drm/i915: debugs: Add support for probing DP sink CRC.
Date: Thu, 16 Jan 2014 18:09:22 +0000 [thread overview]
Message-ID: <20140116180922.GB17903@strange.amr.corp.intel.com> (raw)
In-Reply-To: <20140116175506.GA17903@strange.amr.corp.intel.com>
On Thu, Jan 16, 2014 at 05:55:06PM +0000, Damien Lespiau wrote:
> > + /* Wait 2 vblanks to be sure we will have the correct CRC value */
> > + intel_wait_for_vblank(dev, intel_crtc->pipe);
> > + intel_wait_for_vblank(dev, intel_crtc->pipe);
>
> I think there's a better way to do this. There's a TEST_CRC_COUNT in
> TEST_SINK_MISC that is incremented everytime the CRCs are updated. You
> could:
> * start by grabbing TEST_CRC_COUNT
> * have a loop that waits for a vblank, check if the TEST_CRC_COUNT has
> changed
> * return the new CRC if the update has occured
> * or give up after a number of waits (say 10)
There seem to be support for an interrupt to come from the device to
signal the CRCs are ready (AUTOMATED_TEST_REQUEST of
DEVICE_SERVICE_IRQ_VECTOR), but that's pushing it :)
--
Damien
next prev parent reply other threads:[~2014-01-16 18:09 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-14 18:21 [PATCH 1/2] drm: dp helper: Add DP test sink CRC definition Rodrigo Vivi
2014-01-14 18:21 ` [PATCH 2/2] drm/i915: debugs: Add support for probing DP sink CRC Rodrigo Vivi
2014-01-16 17:55 ` [Intel-gfx] " Damien Lespiau
2014-01-16 18:09 ` Damien Lespiau [this message]
2014-01-25 20:20 ` [Intel-gfx] [PATCH 1/2] drm: dp helper: Add DP test sink CRC definition Daniel Vetter
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