Date: Mon, 2 Oct 2006 00:31:17 +0300 (EEST) From: hsu@bbnetworks.net To: FreeBSD-gnats-submit@FreeBSD.org Subject: kern/103883: DMA is not defaulted on WDMA device Message-ID: <200610012131.k91LVH48000579@true4g-olari1.wlansystems.com> Resent-Message-ID: <200610012140.k91LeFsn025758@freefall.freebsd.org>
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>Number: 103883 >Category: kern >Synopsis: DMA is not defaulted on WDMA device >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Sun Oct 01 21:40:15 GMT 2006 >Closed-Date: >Last-Modified: >Originator: Heikki Suonsivu >Release: FreeBSD 6.1-RELEASE i386 >Organization: bbnetworks.net >Environment: System: FreeBSD true4g-olari1.wlansystems.com 6.1-RELEASE FreeBSD 6.1-RELEASE #0: Sun May 7 04:42:56 UTC 2006 root@opus.cse.buffalo.edu:/usr/obj/usr/src/sys/SMP i386 SIS integrated Vortex86 CPU (possibly the same problem on any system?) >Description: I use CF adapter to connect Compact Flash card to IDE. The adapter and the card apparently support DMA, as it can be enabled by atacontrol mode ad0 WDMA2 The cpu load drops massively, and there is substantial improvement on general performance. The card/adapter does not support UDMA (I do not think that is possible with CF interface at all?), but WDMA2 seems to work. From verbose boot messages it would seem that the driver does indeed recognize WDMA2 being supported, but does not eanble it. ata0-master: pio=PIO4 wdma=WDMA2 udma=UNSUPPORTED cable=40 wire ad0: setting PIO4 on 550 chip ad0: 1983MB <TRANSCEND 20060524> at ata0-master PIO4 ad0: 4061232 sectors [4029C/16H/63S] 1 sectors/interrupt 1 depth queue GEOM: new disk ad0 ad0: Silicon Integrated Systems check1 failed ad0: Adaptec check1 failed ad0: LSI (v3) check1 failed ad0: LSI (v2) check1 failed ad0: FreeBSD check1 failed ATA PseudoRAID loaded Trying to mount root from ufs:/dev/ad0s1a start_init: trying /sbin/init Is this somehow related to the fact that CD/DVD drives do not seem to get DMA mode on by default either? I have tried to tweak stuff in loader.conf with no success. >How-To-Repeat: Get a DMA supporting CF adapter (like new versions from pcengines.ch), and use DMA-supporting CF card. >Fix: Workaround is to set DMA in boot, but that makes booting slower than necessary. DMA would help, in particular with a slow cpu. >Release-Note: >Audit-Trail: >Unformatted:
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