Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932523AbcCLEFA (ORCPT ); Fri, 11 Mar 2016 23:05:00 -0500 Received: from mail-yw0-f169.google.com ([209.85.161.169]:35446 "EHLO mail-yw0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751918AbcCLEE6 (ORCPT ); Fri, 11 Mar 2016 23:04:58 -0500 MIME-Version: 1.0 In-Reply-To: References: <20160303164533.3025.82439.stgit@bhelgaas-glaptop2.roam.corp.google.com> <20160308174558.GC19869@localhost> <20160311232920.GA27552@localhost> Date: Fri, 11 Mar 2016 23:04:57 -0500 Message-ID: Subject: Re: [PATCH v1 00/12] PCI: Rework shadow ROM handling From: Alex Deucher To: Linus Torvalds Cc: Andy Lutomirski , Bjorn Helgaas , Bjorn Helgaas , "linux-pci@vger.kernel.org" , Matthew Garrett , Tony Luck , DRI , Fenghua Yu , Intel Graphics Development , "linux-kernel@vger.kernel.org" , Ralf Baechle , =?UTF-8?Q?Bruno_Pr=C3=A9mont?= , Daniel Stone , =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 925 Lines: 22 On Fri, Mar 11, 2016 at 8:09 PM, Linus Torvalds wrote: > On Fri, Mar 11, 2016 at 4:49 PM, Andy Lutomirski wrote: >> >> FWIW, if I disable all the checks in pci_get_rom_size, I learn that my >> video ROM consists entirely of 0xff bytes. Maybe there just isn't a >> ROM shadow on my laptop. > > I think most laptops end up having the graphics ROM be part of the > regular system flash, and there is no actual rom associated with the > PCI device that is the GPU itself. > > The actual GPU ROM tends to be associated with plug-in cards, not > soldered-down chips in a laptop where they don't want extra flash > chips. Right; on (at least AMD) mobile dGPUs and systems with APUs, the vbios "rom" is part of the sbios image and is set up by the sbios when it runs. The driver either gets it from the legacy vga location or some platform specific method such as ACPI. Alex