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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 5F786C2BC61 for ; Tue, 30 Oct 2018 09:27:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2F17120827 for ; Tue, 30 Oct 2018 09:27:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F17120827 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=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727524AbeJ3SUQ (ORCPT ); Tue, 30 Oct 2018 14:20:16 -0400 Received: from mga11.intel.com ([192.55.52.93]:40858 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726451AbeJ3SUQ (ORCPT ); Tue, 30 Oct 2018 14:20:16 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Oct 2018 02:27:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,444,1534834800"; d="scan'208";a="103722239" Received: from jnikula-mobl3.fi.intel.com (HELO localhost) ([10.237.72.61]) by fmsmga001.fm.intel.com with ESMTP; 30 Oct 2018 02:27:33 -0700 From: Jani Nikula To: Daniel Vetter , Gerd Hoffmann Cc: David Airlie , David Airlie , open list , dri-devel@lists.freedesktop.org, "open list\:DRM DRIVER FOR BOCHS VIRTUAL GPU" Subject: Re: [PATCH v3] drm/bochs: add edid support. In-Reply-To: <20181030090632.GJ21967@phenom.ffwll.local> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20181029134507.7775-1-kraxel@redhat.com> <87in1kejgj.fsf@intel.com> <20181029200520.jfnmvbkng2er5qbc@sirius.home.kraxel.org> <20181030090632.GJ21967@phenom.ffwll.local> Date: Tue, 30 Oct 2018 11:28:24 +0200 Message-ID: <87y3afokav.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 30 Oct 2018, Daniel Vetter wrote: > On Mon, Oct 29, 2018 at 09:05:20PM +0100, Gerd Hoffmann wrote: >> On Mon, Oct 29, 2018 at 07:44:28PM +0200, Jani Nikula wrote: >> > On Mon, 29 Oct 2018, Gerd Hoffmann wrote: >> > > Recent qemu (latest master branch, upcoming 3.1 release) got support >> > > for EDID data. This patch adds guest driver support. >> > > >> > > EDID support in qemu is not (yet) enabled by default, so please use >> > > 'qemu -device VGA,edid=on' for testing. >> > >> > Any chance of making this use drm_get_edid() (requires an i2c_adapter) >> > or at least drm_do_get_edid()? >> >> I'll have a look at using drm_do_get_edid(). drm_get_edid() will not >> fly as there is no i2c adapter in the first place. > > Hm, not sure that makes sense. drm_do_get_edid is to handle the real-world > flakiness of sinks (it's where all the retry logic resides), if you don't > have a i2c_adapater (because the hw has some magic "give me an edid" > block). For virtual hw we hopefully don't randomly drop bits on the floor > between the guest and host. Imo totally fine as-is. > > E.g. we also don't feed the VBT edid through drm_do_get_edid either. But nowadays we do handle the debugfs EDID override and the EDID firmware loading in drm_do_get_edid(), so using that gives you those features. BR, Jani. -- Jani Nikula, Intel Open Source Graphics Center