Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 4 Oct 2001 04:58:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 4 Oct 2001 04:58:13 -0400 Received: from web11805.mail.yahoo.com ([216.136.172.159]:57871 "HELO web11805.mail.yahoo.com") by vger.kernel.org with SMTP id ; Thu, 4 Oct 2001 04:58:04 -0400 Message-ID: <20011004085833.29209.qmail@web11805.mail.yahoo.com> Date: Thu, 4 Oct 2001 10:58:33 +0200 (CEST) From: =?iso-8859-1?q?Etienne=20Lorrain?= Subject: specific optimizations for unaccelerated framebuffers To: linux-kernel@vger.kernel.org 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 Just a question: Has anybody ever tried to have a copy of the video memory in the main memory. All the software would access the copy in main memory, and the standart DMA is used (permanently) to update the real video memory. Maybe a 32 bit int could be used to skip unmodified 64K pages (1 bit per page). The main processor would never have to wait for PCI read/writes. In fact the question is: what kind of bandwidth can we have from a standart PC DMA (memory to memory copy)? The other problem could be the addresses limits, but using the VESA1 interface (window switching at 0xA0000), the video memory image below 16 Mb and known I/O ports (see Gujin) would solve that. Someone has bandwidth measures? Etienne. ___________________________________________________________ Do You Yahoo!? -- Un e-mail gratuit @yahoo.fr ! Yahoo! Courrier : http://fr.mail.yahoo.com - 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/