Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752209AbaGKG3x (ORCPT ); Fri, 11 Jul 2014 02:29:53 -0400 Received: from mail-wi0-f170.google.com ([209.85.212.170]:44717 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751146AbaGKG3w (ORCPT ); Fri, 11 Jul 2014 02:29:52 -0400 Date: Fri, 11 Jul 2014 08:29:56 +0200 From: Daniel Vetter To: "Tian, Kevin" Cc: Daniel Vetter , Paolo Bonzini , "xen-devel@lists.xensource.com" , "airlied@linux.ie" , "intel-gfx@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , "qemu-devel@nongnu.org" , "dri-devel@lists.freedesktop.org" , "Chen, Tiejun" , "Kay, Allen M" Subject: Re: [Intel-gfx] [RFC][PATCH] gpu:drm:i915:intel_detect_pch: back to check devfn instead of check class type Message-ID: <20140711062956.GP17271@phenom.ffwll.local> Mail-Followup-To: "Tian, Kevin" , Paolo Bonzini , "xen-devel@lists.xensource.com" , "airlied@linux.ie" , "intel-gfx@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , "qemu-devel@nongnu.org" , "dri-devel@lists.freedesktop.org" , "Chen, Tiejun" , "Kay, Allen M" References: <1403171631-3452-1-git-send-email-tiejun.chen@intel.com> <53A42DAA.80406@redhat.com> <53A692F9.3060200@intel.com> <53AA70C0.2000806@redhat.com> <20140707144917.GZ5821@phenom.ffwll.local> <53BAB569.5000709@redhat.com> <20140707175402.GS5821@phenom.ffwll.local> <53BADFC6.9060101@redhat.com> <20140707184006.GU5821@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: Linux phenom 3.15.0-rc3+ User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 10, 2014 at 09:08:24PM +0000, Tian, Kevin wrote: > actually I'm curious whether it's still necessary to __detect__ PCH. Could > we assume a 1:1 mapping between GPU and PCH, e.g. BDW already hard > code the knowledge: > > } else if (IS_BROADWELL(dev)) { > dev_priv->pch_type = PCH_LPT; > dev_priv->pch_id = > INTEL_PCH_LPT_LP_DEVICE_ID_TYPE; > DRM_DEBUG_KMS("This is Broadwell, assuming " > "LynxPoint LP PCH\n"); > > Or if there is real usage on non-fixed mapping (not majority), could it be a > better option to have fixed mapping as a fallback instead of leaving as > PCH_NONE? Then even when Qemu doesn't provide a special tweaked PCH, > the majority case just works. I guess we can do it, at least I haven't seen any strange combinations in the wild outside of Intel ... -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/