From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [PATCH] drm/i915: Implement pipe CSC based limited range RGB output Date: Fri, 8 Feb 2013 22:43:33 +0200 Message-ID: <20130208204333.GL9135@intel.com> References: <1358529098-31596-1-git-send-email-ville.syrjala@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTP id CEBA5E5D06 for ; Fri, 8 Feb 2013 12:43:38 -0800 (PST) Content-Disposition: inline In-Reply-To: <1358529098-31596-1-git-send-email-ville.syrjala@linux.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Fri, Jan 18, 2013 at 07:11:38PM +0200, ville.syrjala@linux.intel.com wro= te: > From: Ville Syrj=E4l=E4 > = > HSW no longer has the PIPECONF bit for limited range RGB output. > Instead the pipe CSC unit must be used to perform that task. > = > The CSC pre offset are set to 0, since the incoming data is full > [0:255] range RGB, the coefficients are programmed to compress the > data into [0:219] range, and then we use either the CSC_MODE black > screen offset bit, or the CSC post offsets to shift the data to > the correct [16:235] range. > = > Also have to change the confiuration of all planes so that the > data is sent through the pipe CSC unit. For simplicity send the > plane data through the pipe CSC unit always, and in case full > range output is requested, the pipe CSC unit is set up with an > identity transform to pass the plane data through unchanged. > = > I've been told by some hardware people that the use of the pipe > CSC unit shouldn't result in any measurable increase in power > consumption numbers. > = > Signed-off-by: Ville Syrj=E4l=E4 > --- > Note that I haven't actually tested this on HSW. I did test the earlier > prototype version on ILK and IVB. The pipe CSC unit on ILK isn't programm= ed > in quite the same as on HSW, but the IVB unit _should_ be identical to HS= W. > = > The main risk involves the coefficient registers. If the channel mapping > changed for some reason, we could get swapped channels. For some reason > reality and documenation didn't seem to agree how the channels are mapped > even on ILK and IVB. So I'd like someone to try this out on HSW to make > sure the output still looks correct. FYI I just tested this on a HSW box, and all the colors look correct. I also verified that the pipeconf color range bit is well and truly gone (hw won't allow you to even set it). So Daniel, I think this can go in as is. -- = Ville Syrj=E4l=E4 Intel OTC