On Tue, 17 Apr 2007, Jesus Jr M Salvo wrote: > Hi All, > > Just like to provide feedback about getting the Comsol UHD-3542 USB > 2.0 hard drive enclosure on 2.6 kernel. I am using FC6 with kernel > 2.6.20-1.2933.fc6, and after setting the up enclosure, here's what I > initially got: > > Apr 17 21:25:47 localhost kernel: usb 2-2: new high speed USB device > using ehci_hcd and address 4 > Apr 17 21:25:58 localhost kernel: usb 2-2: device not accepting > address 4, error -110 > Apr 17 21:25:59 localhost kernel: usb 2-2: new high speed USB device > using ehci_hcd and address 5 > Apr 17 21:26:10 localhost kernel: usb 2-2: device not accepting > address 5, error -110 > Apr 17 21:26:10 localhost kernel: usb 2-2: new high speed USB device > using ehci_hcd and address 6 > Apr 17 21:26:21 localhost kernel: usb 2-2: device not accepting > address 6, error -110 > Apr 17 21:26:21 localhost kernel: usb 2-2: new high speed USB device > using ehci_hcd and address 7 > Apr 17 21:26:31 localhost kernel: usb 2-2: device not accepting > address 7, error -110 > > > I tried plugging in to a different USB port, powering it on and off to no > avail. > What worked was unloading the ehci_hcd kernel module, like so: > > [EMAIL PROTECTED] jsalvo]# /sbin/rmmod ehci_hcd > > > ... and then all of a sudden, it sees the hard drive. What confuses me > though is that once ehci_hcd was unloaded, it then uses a different > kernel module ... ohci_hcd to actually access the hard drive in the > hard drive enclosure, as shown below: > > > Apr 17 21:55:45 localhost kernel: usb 1-2: new full speed USB device > using ohci_hcd and address 7 > Apr 17 21:55:47 localhost kernel: usb 1-2: configuration #1 chosen from 1 > choice > Apr 17 21:55:47 localhost kernel: scsi4 : SCSI emulation for USB Mass > Storage devices > Apr 17 21:55:52 localhost kernel: scsi 4:0:0:0: Direct-Access > WDC WD800JB-00ET 77.0 PQ: 0 ANSI: 0 CCS > Apr 17 21:55:52 localhost kernel: SCSI device sdb: 156301488 512-byte > hdwr sectors (80026 MB) > Apr 17 21:55:52 localhost kernel: sdb: test WP failed, assume Write Enabled > Apr 17 21:55:52 localhost kernel: sdb: assuming drive cache: write through > Apr 17 21:55:52 localhost kernel: SCSI device sdb: 156301488 512-byte > hdwr sectors (80026 MB) > Apr 17 21:55:52 localhost kernel: sdb: test WP failed, assume Write Enabled > Apr 17 21:55:52 localhost kernel: sdb: assuming drive cache: write through > Apr 17 21:55:52 localhost kernel: sdb: sdb1 sdb2 sdb3 sdb4 < sdb5 > sdb6 sdb7 sdb8 sdb9 sdb10 sdb11 > > Apr 17 21:55:52 localhost kernel: sd 4:0:0:0: Attached scsi disk sdb > Apr 17 21:55:52 localhost kernel: sd 4:0:0:0: Attached scsi generic sg1 type 0 > Apr 17 21:55:58 localhost kernel: kjournald starting. Commit interval 5 > seconds > Apr 17 21:55:58 localhost kernel: EXT3 FS on sdb7, internal journal > Apr 17 21:55:58 localhost kernel: EXT3-fs: mounted filesystem with > ordered data mode. > Apr 17 21:55:58 localhost hald: mounted /dev/sdb7 on behalf of uid 500 > > > Question is: > 1) Because I am using ochi_hcd and not ehci_hcd, does that mean I am > not really using USB 2.0 ??
It means you are not running at high speed. ohci-hcd supports only 12 Mb/s whereas ehci-hcd supports 480 Mb/s. > 2) Why did it try ehci_hcd in the first place and not ohci_hcd ? Because the device itself is a high-speed device, although it is capable of falling back to full speed if the computer doesn't support high speed (for example, if ehci-hcd isn't loaded). The real question is why the device failed to work at high speed. It could be a problem in the device, a problem in your computer's EHCI controller, or a problem in the USB cabling. To try and pinpoint the problem, you should try connecting the device to a different computer and try connecting different high-speed devices to your computer (with ehci-hcd loaded, of course). Alan Stern ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Linux-usb-users@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
