Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 10 Oct 2002 17:02:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 10 Oct 2002 17:02:02 -0400 Received: from va.cs.wm.edu ([128.239.2.31]:55311 "EHLO va.cs.wm.edu") by vger.kernel.org with ESMTP id ; Thu, 10 Oct 2002 17:02:00 -0400 Date: Thu, 10 Oct 2002 17:07:42 -0400 From: Bruce Lowekamp To: linux-kernel@vger.kernel.org Subject: 2.4.20-pre10-ac1/2.5.41 hda: DMA disabled, but it's not Message-ID: <11730000.1034284062@chorus.cs.wm.edu> X-Mailer: Mulberry/3.0.0a4 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3693 Lines: 82 This is a report of a suspicious message that is not really a problem, as far as I can tell. With both 2.4.20-pre10-ac1 and 2.5.41 on an A7V266-E MB, hard drives hooked up to the VIA vt8233 IDE controller, on bootup messages about hda: DMA disabled appear, but as far as I can tell, it's not disabled, at least not by the time I can log into the system, and copying /proc/ide/via to /tmp right after / is remounted rw shows that it is UDMA enabled at that point. This is a rh7.3 system. I've tried to rule out that hdparm or sysctl is being run somewhere. Nothing appears in rc.local or one of the scripts in /etc/rc.d/init.d. /etc/sysctl.conf doesn't seem to have anything that would enable DMA, and USE_DMA=1 is commented out in /etc/sysconfig/harddisks. Once the system is up, DMA appears to be enabled on hda. /proc/ide/via shows it enabled, and bonnie++ gets good throughput (higher than 2.4.19 on sequential reads, slightly slower on writes). If what's happening is that DMA is being disabled, then enabled, maybe either the disabled message should be removed or a message that it's being enabled should be added, because right now it looks rather suspicious. Thanks, Bruce The messages that appear on bootup look like: ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx VP_IDE: VIA vt8233 (rev 00) IDE UDMA100 controller on pci00:11.1 ide0: BM-DMA at 0x9400-0x9407, BIOS settings: hda:DMA, hdb:pio ide1: BM-DMA at 0x9408-0x940f, BIOS settings: hdc:DMA, hdd:pio hda: IC35L060AVER07-0, ATA DISK drive hda: DMA disabled blk: queue c030afc0, I/O limit 4095Mb (mask 0xffffffff) hdc: TOSHIBA DVD-ROM SD-M1612, ATAPI CD/DVD-ROM drive hdc: DMA disabled ide0 at 0x1f0-0x1f7,0x3f6 on irq 14 ide1 at 0x170-0x177,0x376 on irq 15 hda: host protected area => 1 hda: 120103200 sectors (61493 MB) w/1916KiB Cache, CHS=7476/255/63, UDMA(100) hdc: ATAPI 48X DVD-ROM drive, 512kB Cache, UDMA(33) ..skipping a bit.. hdc: DMA disabled But /proc/ide/via is: ----------VIA BusMastering IDE Configuration---------------- Driver Version: 3.34 South Bridge: VIA vt8233 Revision: ISA 0x0 IDE 0x6 Highest DMA rate: UDMA100 BM-DMA base: 0x9400 PCI clock: 33.3MHz Master Read Cycle IRDY: 0ws Master Write Cycle IRDY: 0ws BM IDE Status Register Read Retry: yes Max DRDY Pulse Width: No limit -----------------------Primary IDE-------Secondary IDE------ Read DMA FIFO flush: yes yes End Sector FIFO flush: no no Prefetch Buffer: yes no Post Write Buffer: yes no Enabled: yes yes Simplex only: no no Cable Type: 80w 80w -------------------drive0----drive1----drive2----drive3----- Transfer Mode: UDMA PIO PIO PIO Address Setup: 30ns 120ns 30ns 120ns Cmd Active: 90ns 90ns 90ns 90ns Cmd Recovery: 30ns 30ns 30ns 30ns Data Active: 90ns 330ns 90ns 330ns Data Recovery: 30ns 270ns 30ns 270ns Cycle Time: 20ns 600ns 120ns 600ns Transfer Rate: 99.9MB/s 3.3MB/s 16.6MB/s 3.3MB/s - 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/