From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98899C4332D for ; Thu, 19 Mar 2020 17:06:27 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 743FB2072D for ; Thu, 19 Mar 2020 17:06:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 743FB2072D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F3C2989CDE; Thu, 19 Mar 2020 17:06:26 +0000 (UTC) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7274D89BA5 for ; Thu, 19 Mar 2020 17:06:25 +0000 (UTC) IronPort-SDR: zZHq/YLBVendJav7KRzgZ0ZxJJApMFgi+29Sy32GDLZXl6yDePD6su754ZKqbVb7UD9Eo8Ylsq oSBJdQyEo/hQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Mar 2020 10:06:24 -0700 IronPort-SDR: Ok66OpAvMjaoNWTeDfGEnvKgVFaDTOCdCyhFGTU6UIdfiw0Lfw6s1oN6RmvdFYD5OBXHh6eKE5 p2Qvs0OXX0Mg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,572,1574150400"; d="scan'208";a="263794539" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by orsmga002.jf.intel.com with SMTP; 19 Mar 2020 10:06:21 -0700 Received: by stinkbox (sSMTP sendmail emulation); Thu, 19 Mar 2020 19:06:20 +0200 Date: Thu, 19 Mar 2020 19:06:20 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Hans de Goede Message-ID: <20200319170620.GO13686@intel.com> References: <20200319163844.22783-1-ville.syrjala@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Patchwork-Hint: comment User-Agent: Mutt/1.10.1 (2018-07-13) Subject: Re: [Intel-gfx] [PATCH 1/3] drm/i915: Try to use fast+narrow link on eDP again and fall back to the old max strategy on failure X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jani Nikula , Albert Astals Cid , intel-gfx@lists.freedesktop.org, Matteo Iervasi , Emanuele Panigati Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, Mar 19, 2020 at 05:53:08PM +0100, Hans de Goede wrote: > Hi, > = > On 3/19/20 5:38 PM, Ville Syrjala wrote: > > From: Ville Syrj=E4l=E4 > > = > > Some new eDP panels don't like to operate at the max parameters, and > > instead we need to go for an optimal confiugration. That unfortunately > > doesn't work with older eDP panels which are generally only guaranteed > > to work at the max parameters. > > = > > To solve these two conflicting requirements let's start with the optimal > > setup, and if that fails we start again with the max parameters. The > > downside is probably an extra modeset when we switch strategies but > > I don't see a good way to avoid that. > > = > > For a bit of history we first tried to go for the fast+narrow in > > commit 7769db588384 ("drm/i915/dp: optimize eDP 1.4+ link config > > fast and narrow"). but that had to be reverted due to regression > > on older panels in commit f11cb1c19ad0 ("drm/i915/dp: revert back > > to max link rate and lane count on eDP"). So now we try to get > > the best of both worlds by using both strategies. > > = > > v2: Deal with output_bpp and uapi vs. hw state split > > Reword some comments > = > I'm wondering if, at least for the fastset case, but also > for later modesets I guess, it would not be better to > first check if the link is already setup (panel already on) > and then check if the existing parameters match our min/max > criteria and if they do continue with those settings? > = > Doing something like this would likely also fix: > https://gitlab.freedesktop.org/drm/intel/issues/1476 Yeah, I've thought about doing that. It's a bit ugly though, and probably requires some actual thought so that we don't end up doing something stupid. -- = Ville Syrj=E4l=E4 Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx