From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jani Nikula Subject: Re: PROBLEM: i915 Haswell KMS wrong maximum resolution Date: Mon, 31 Mar 2014 10:43:28 +0300 Message-ID: <87vbuuertr.fsf@intel.com> References: <20140330203645.22961085@neptune.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTP id A51D26E1CB for ; Mon, 31 Mar 2014 00:43:01 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Kenneth de Mello , Bruno =?utf-8?Q?Pr=C3=A9mon?= =?utf-8?Q?t?= Cc: intel-gfx@lists.freedesktop.org, "Syrjala, Ville" List-Id: intel-gfx@lists.freedesktop.org On Sun, 30 Mar 2014, Kenneth de Mello wrote: > What about dual-link DVI? I though the additional link addressed the > pixel clock limitation. Has it only been using a single link this entire > time, and it's only worked by ignoring the maximum dotclock, so in other > words, the fact it works at all is the bug? > > Also, the commit that rejects mode exceeding 165MHz states: > > "Single-link DVI max dotclock is 165MHz. Filter out modes with higher > dotclock when the monitor doesn't support HDMI." > > Does this mean HDMI in general? This monitor does support HDMI, but the > maximum resolution when using the physical HDMI ports is 1920x1080. > > What is the solution here, to switch to displayport if I want to use kernel > 3.13.7 and beyond? (This is fine, I just need to know so I can buy the > cable). For further details please see the bug report [1]. The reason for the change was that modes with higher than 165 MHz dotclock are invalid for single-link DVI. We don't support dual-link DVI natively. Thus this is about HDMI->DVI adapters which are either dual-link DVI (Ville says highly unlikely) or single-link DVI that allow higher than 165 MHz dotclock in the monitor end. I'm not sure how we could distinguish that from a regular single-link DVI that *is* bound by the maximum dotclock. Product details for the adapter you're using might be interesting. BR, Jani. [1] https://bugzilla.kernel.org/show_bug.cgi?id=72961 -- Jani Nikula, Intel Open Source Technology Center