From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Schulman Subject: dc395x: CD writer causes endless "sg_to_virt failed" loop Date: Sat, 27 Mar 2004 09:57:39 -0500 Sender: linux-scsi-owner@vger.kernel.org Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit Return-path: Received: from main.gmane.org ([80.91.224.249]:30923 "EHLO main.gmane.org") by vger.kernel.org with ESMTP id S261766AbUC0PAM (ORCPT ); Sat, 27 Mar 2004 10:00:12 -0500 Received: from root by main.gmane.org with local (Exim 3.35 #1 (Debian)) id 1B7FIA-0006WQ-00 for ; Sat, 27 Mar 2004 16:00:10 +0100 Received: from pcp04415756pcs.nrockv01.md.comcast.net ([69.140.191.214]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 27 Mar 2004 16:00:10 +0100 Received: from andrex by pcp04415756pcs.nrockv01.md.comcast.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 27 Mar 2004 16:00:10 +0100 List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org I have a Tekram DC395UW card, running in Debian with kernel 2.6.3 and the dc395x driver from the kernel source. Attached to the card are a Seagate Travan NS20 tape drive, and an HP 9200i CD writer: Mar 27 09:50:53 helium kernel: dc395x: Tekram DC395(U/UW/F), DC315(U) - ASIC TRM-S1040 v2.04, 2003/05/19 Mar 27 09:50:53 helium kernel: dc395x: Used settings: AdapterID=07, Speed=0(20.0MHz), dev_mode=0x77 Mar 27 09:50:53 helium kernel: dc395x: AdaptMode=0x0f, Tags=4(16), DelayReset=1s Mar 27 09:50:53 helium kernel: dc395x: (Wide) Connectors: int50 Termination: Auto Low High Mar 27 09:50:53 helium kernel: dc395x: Performing initial SCSI bus reset Mar 27 09:50:53 helium kernel: scsi2 : Tekram DC395(U/UW/F), DC315(U) - ASIC TRM-S1040 v2.04, 2003/05/19 Mar 27 09:50:55 helium kernel: dc395x: Target 02: Sync: 100ns Offset 15 (10.0 MB/s) Mar 27 09:50:55 helium kernel: Vendor: Seagate Model: STT20000N Rev: 7A61 Mar 27 09:50:55 helium kernel: Type: Sequential-Access ANSI SCSI revision: 02 Mar 27 09:50:55 helium scsi.agent[2072]: tape at /devices/pci0000:00/0000:00:1e.0/0000:02:04.0/host2/2:0:2:0 Mar 27 09:50:55 helium kernel: st: Version 20040122, fixed bufsize 32768, s/g segs 256 Mar 27 09:50:55 helium kernel: Attached scsi tape st0 at scsi2, channel 0, id 2, lun 0 Mar 27 09:50:55 helium kernel: st0: try direct i/o: yes, max page reachable by HBA 1048575 Mar 27 09:50:56 helium kernel: dc395x: Target 06: Sync: 100ns Offset 15 (10.0 MB/s) Mar 27 09:50:56 helium kernel: Vendor: HP Model: CD-Writer+ 9200 Rev: 1.0e Mar 27 09:50:56 helium kernel: Type: CD-ROM ANSI SCSI revision: 04 Mar 27 09:50:56 helium scsi.agent[2085]: cdrom at /devices/pci0000:00/0000:00:1e.0/0000:02:04.0/host2/2:0:6:0 Mar 27 09:51:03 helium kernel: sr0: scsi3-mmc drive: 32x/32x writer cd/rw xa/form2 cdda tray The tape drive works normally. But as soon as I try to use the CD drive-- by, for example, trying to mount or burn a CD-- my console and syslog begin to fill up with "dc395x: sg_to_virt failed!" messages-- several hundred per second. I can't unload the driver, and my system becomes sluggish. Once this starts I've often had to force a case reboot in order to restore normal operation. As you can imagine, I'm not happy about that. I'm frustrated by this problem because the drive worked fine with earlier kernels. It definitely worked fine with 2.6.0-test4 and -test9. I don't want to go back to an earlier kernel, because of other security and hardware issues. My 2.6.3 kernel works perfectly, except that now my CD writer is broken. Any help would be much appreciated. I'm willing to try any patches or diagnostics. Thanks, Andrew.