From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261727AbTDQPdt (ORCPT ); Thu, 17 Apr 2003 11:33:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261743AbTDQPds (ORCPT ); Thu, 17 Apr 2003 11:33:48 -0400 Received: from 81-2-122-30.bradfords.org.uk ([81.2.122.30]:4224 "EHLO 81-2-122-30.bradfords.org.uk") by vger.kernel.org with ESMTP id S261727AbTDQPds (ORCPT ); Thu, 17 Apr 2003 11:33:48 -0400 From: John Bradford Message-Id: <200304171547.h3HFljoK000140@81-2-122-30.bradfords.org.uk> Subject: Re: Subtle semantic issue with sleep callbacks in drivers To: jgarzik@pobox.com (Jeff Garzik) Date: Thu, 17 Apr 2003 16:47:45 +0100 (BST) Cc: john@grabjohn.com (John Bradford), alan@lxorguk.ukuu.org.uk (Alan Cox), mochel@osdl.org (Patrick Mochel), andrew.grover@intel.com (Grover Andrew), benh@kernel.crashing.org (Benjamin Herrenschmidt), linux-kernel@vger.kernel.org (Linux Kernel Mailing List) In-Reply-To: <20030417150926.GA25402@gtf.org> from "Jeff Garzik" at Apr 17, 2003 11:09:26 AM X-Mailer: ELM [version 2.5 PL6] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > > The video BIOS on a card often contains information that is found > > > -nowhere- else. Not in the chip docs. Not in a device driver. > > > Such information can and does vary from board-to-board, such as RAM > > > timings, while the chip remains unchanged. > > > > Incidently, what happens if we: > > > > * Suspend > > * Swap VGA card with another one > > * Restore > > When it breaks, you get to keep both pieces. > > That's a "Don't Do That" issue for any hardware between suspend > and resume. Hmm, well what about with a PCI hotswap capable board - presumably then we could have the situation where a new VGA card appears that we _have_ to POST? John.