From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Richter Subject: Re: i830 watermark problems - status? Date: Mon, 25 Nov 2013 16:55:47 +0100 Message-ID: <52937303.5000209@math.tu-berlin.de> References: <1385093524-22276-1-git-send-email-keithp@keithp.com> <20131122102632.GQ27344@phenom.ffwll.local> <86d2lsem3m.fsf@miki.keithp.com> <20131122221213.GA3234@tokamak.local> <16967_1385369810_529310D2_16967_15891_1_20131125085723.GW27344@phenom.ffwll.local> <52936944.1080906@math.tu-berlin.de> <26487_1385392973_52936B4D_26487_126_1_20131125152331.GB27344@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from medousa.rus.uni-stuttgart.de (medousa.rus.uni-stuttgart.de [129.69.192.4]) by gabe.freedesktop.org (Postfix) with ESMTP id 3901BFAA15 for ; Mon, 25 Nov 2013 07:56:23 -0800 (PST) In-Reply-To: <26487_1385392973_52936B4D_26487_126_1_20131125152331.GB27344@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 Am 25.11.2013 16:23, schrieb Daniel Vetter: > On Mon, Nov 25, 2013 at 04:14:12PM +0100, Thomas Richter wrote: >> Hi Daniel, hi group, >> >> just being curious - what is the status of the i830 watermark >> problems, i.e. the state of affairs >> concerning that the i830 does not allow the maximum watermark value, >> but requires a "headroom" of eight entries to >> avoid flickering. >> >> I provided a patch for this a while ago, but this seems to go >> nowhere. Just to remind you: The current code does not create >> a stable image on i830 based devices, even if only an internal >> display is connected. >> >> I provided two possible attacks to the problem: A quick and dirty >> method which checks for the maximum value for >> i830 manually, or an overall solution which adds a "minimum" >> watermark value for all supported chipsets. >> >> Please let me know how to proceed. > I seem to be too swamped with firedrills and bugs atm to get the polished > version in. The problem with just a quick hack is that we still need to > switch i830M to the dual-pipe watermark function, and somehow my patch to > do so seems to be broken. At least you've said that the kernel still seems > to hit the single-watermark version of the function. > > So atm I'm a bit stalled on this :( But if you can track this down I'd go > with a quick hack to enforce the minimum of 8 or so in the dual-pipe > watermark function shared by gen2/3. Not a problem on my side, but it would be a "bad thing"(tm) to release a kernel that leaves a i830 based architecture essentially non-usable. Well, if you depend on a local display, that is. (-; Greetings, Thomas