From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265163AbUEMXth (ORCPT ); Thu, 13 May 2004 19:49:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265192AbUEMXth (ORCPT ); Thu, 13 May 2004 19:49:37 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:46539 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S265163AbUEMXtf (ORCPT ); Thu, 13 May 2004 19:49:35 -0400 Message-ID: <40A40982.60202@pobox.com> Date: Thu, 13 May 2004 19:49:22 -0400 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030703 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Andrew Morton CC: Robert.Picco@hp.com, linux-kernel@vger.kernel.org, venkatesh.pallipadi@intel.com Subject: Re: [PATCH] HPET driver References: <40A3F805.5090804@hp.com> <40A40204.1060509@pobox.com> <20040513164226.7efb2a83.akpm@osdl.org> In-Reply-To: <20040513164226.7efb2a83.akpm@osdl.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > Jeff Garzik wrote: > >>>+ vma->vm_flags |= (VM_IO | VM_SHM | VM_LOCKED); >>>+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); >>>+ addr = __pa(addr); >> >>where did these flags come from? don't you just want VM_RESERVED? > > > VM_IO is the way to mark mmapped I/O devices. > > vma->vm_flags |= VM_IO; > > should be sufficient here. > > hm, I'm trying to decrypt how the driver accesses the hardware. It's > taking copies of kernel virtual addresses based off hpet_virt_address, but > there are no readl's or writel's in there. Is the actual device access > done over in time_hpet.c? HPET writes into RAM at magic addresses, so it's not really a bus address. Thus I think only VM_RESERVED is needed... Jeff