From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [PATCH 4/4] drm/i915: Allow HDMI+HDMI cloning on g4x Date: Wed, 5 Mar 2014 20:41:10 +0200 Message-ID: <20140305184110.GU3852@intel.com> References: <1393856131-16961-1-git-send-email-ville.syrjala@linux.intel.com> <1393856131-16961-5-git-send-email-ville.syrjala@linux.intel.com> <20140305182158.GW17001@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id 47377FA817 for ; Wed, 5 Mar 2014 10:41:27 -0800 (PST) Content-Disposition: inline In-Reply-To: <20140305182158.GW17001@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org To: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Wed, Mar 05, 2014 at 07:21:58PM +0100, Daniel Vetter wrote: > On Mon, Mar 03, 2014 at 04:15:31PM +0200, ville.syrjala@linux.intel.com w= rote: > > From: Ville Syrj=E4l=E4 > > = > > BSpec is a bit unclear whether HDMI+HDMI cloning should work on g4x. > > Tests on real hardware say that it does. Since g4x can't send > > infoframes to more than one HDMI port anyway, we don't lose anything > > by allow it. > > = > > For PCH platforms BSpec explicitly forbids HDMI+HDMI cloning. > > = > > Whether HDMI+HDMI cloning might also work on VLV is a bit unclear, but > > since we'd at least lose the capability of sending infoframes to more > > than one cloned HDMI port, it doesn't seem like a good idea to allow it. > > = > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=3D73850 > > Signed-off-by: Ville Syrj=E4l=E4 > > --- > > drivers/gpu/drm/i915/intel_hdmi.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > = > > diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/i= ntel_hdmi.c > > index 9dacb33..4eb30d8 100644 > > --- a/drivers/gpu/drm/i915/intel_hdmi.c > > +++ b/drivers/gpu/drm/i915/intel_hdmi.c > > @@ -1316,6 +1316,13 @@ void intel_hdmi_init(struct drm_device *dev, int= hdmi_reg, enum port port) > > intel_encoder->type =3D INTEL_OUTPUT_HDMI; > > intel_encoder->crtc_mask =3D (1 << 0) | (1 << 1) | (1 << 2); > > intel_encoder->cloneable =3D 1 << INTEL_OUTPUT_ANALOG; > > + /* > > + * BSpec is unclear about HDMI+HDMI cloning on g4x, but it seems > > + * to work on real hardware. And since g4x can send infoframes to > > + * only one port anyway, nothing is lost by allowing it. > > + */ > > + if (IS_G4X(dev)) > = > Why restrict this? The per-encoder infoframe setup should dtrt everywhere > else I hope ... As stated in the commit message, BSpec forbids it for PCH. Additionally the video DIP lives is in the transcoder, and one transcoder apparently can't send infoframes to more than one port. I'm not sure how this stuff actually gets routed in the hardware, but the video DIP control register ususally has its own port selector bits which can only select one port at a time. -- = Ville Syrj=E4l=E4 Intel OTC