From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 17 Jan 2001 14:46:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 17 Jan 2001 14:46:12 -0500 Received: from madaket.netwizards.net ([208.164.216.19]:44557 "EHLO madaket.netwizards.net") by vger.kernel.org with ESMTP id ; Wed, 17 Jan 2001 14:45:54 -0500 Date: Wed, 17 Jan 2001 11:46:36 -0800 From: hgp-linux@madaket.netwizards.net Message-Id: <200101171946.LAA25426@madaket.netwizards.net> To: linux-kernel@vger.kernel.org Subject: Strange mm problem?? Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I'm having a crazy mm problem with the new 2.4.0 kernel. I've got a device in which I do DMA i/o from user space. I have a dd which allocs mem (for use as a DMA staging area) and then I use remap_page_range() to map it into user land (via the mmap() interface). I was using __get_dma_pages(), the MAP_NR macro, and mem_map_reserve() to allocate and reserve the mem. It works great in 2.2.12 and 2.4.0-test4. Now with 2.4.0 production, I borrowed the uvirt_to_kva(), uvirt_to_bus(), kvirt_to_pa() and rvmalloc() functions from drivers/media/video/bttv-driver.c Now here's the wierd part: Memory is allocated ok and I can read to and write from it in the dd. But in the userland application, I can write to it OK, but all reads return 0xff! I'm sure I'm doing something wrong but can't figure out what! Any assistance would be appreciated. REgards, Howard G Page - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/