2004-10-14 11:31:48

by Ganesan Rajagopal

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Subject: Linux 2.6.x wrongly recognizes USB 2.0 DVD writer

Hi,

I have a NEC ND-2500A DVD writer in a ByteCC USB 2.0 external enclosure.
It's recognized perfectly in 2.4.27 (Debian kernel-image-2.4.27-1-686
package)

========
scsi2 : SCSI emulation for USB Mass Storage
Vendor: _NEC Model: DVD_RW ND-2500A
Type: CD-ROM ANSI SCSI revision: 02
Attached scsi CD-ROM sr1 at scsi2, channel 0, id 0, lun 0
sr1: scsi-1 drive
USB Mass Storage support registered.
========

When I boot 2.6.8 (Debian kernel-image-2.6.8-1-686 package), I get

========
scsi3 : SCSI emulation for USB Mass Storage devices
Vendor: Revoltec Model: USB/IDE Bridge ( Rev: 0103
Type: Direct-Access ANSI SCSI revision: 02
Attached scsi removable disk sdb at scsi3, channel 0, id 0, lun 0
USB Mass Storage device found at 4
========

Any body else facing this problem?

Ganesan




2004-10-14 13:02:07

by John Stoffel

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Subject: Re: Linux 2.6.x wrongly recognizes USB 2.0 DVD writer


Ganesan> I have a NEC ND-2500A DVD writer in a ByteCC USB 2.0 external
Ganesan> enclosure. It's recognized perfectly in 2.4.27 (Debian
Ganesan> kernel-image-2.4.27-1-686 package)

I've got a ByteCC external enclosure too, and I can't get it to work
reliably under Linux or Windows under Firewire. I'd return it and get
something better.

Also, the 2.6 ieee1394 sbp2 driver isn't the best at detecting these
things. And if it does, it doesn't always work well with drives in
there as well. I've been having tons of problems and I basically gave
up.

John

2004-10-14 13:28:38

by Ganesan Rajagopal

[permalink] [raw]
Subject: Re: Linux 2.6.x wrongly recognizes USB 2.0 DVD writer

John Stoffel wrote:

>Ganesan> I have a NEC ND-2500A DVD writer in a ByteCC USB 2.0 external
>Ganesan> enclosure. It's recognized perfectly in 2.4.27 (Debian
>Ganesan> kernel-image-2.4.27-1-686 package)
>
>I've got a ByteCC external enclosure too, and I can't get it to work
>reliably under Linux or Windows under Firewire. I'd return it and get
>something better.
>
Thanks for the info. As I mentioned, the enclosure works flawlessly for
me under 2.4.27. It's getting detected incorrectly only in 2.6.x.
Another user reported a similar problem but was able to get dvd burning
working by removing the checks from the writing tool. So, it looks like
detection has been messed up only in 2.6.x.

Once again, 2.6.8 reports it as

======
scsi3 : SCSI emulation for USB Mass Storage devices
Vendor: Revoltec Model: USB/IDE Bridge ( Rev: 0103
Type: Direct-Access ANSI SCSI revision: 02
Attached scsi removable disk sdb at scsi3, channel 0, id 0, lun 0
======

whereas 2.4.27 correctly reports

========
scsi2 : SCSI emulation for USB Mass Storage
Vendor: _NEC Model: DVD_RW ND-2500A
Type: CD-ROM ANSI SCSI revision: 02
Attached scsi CD-ROM sr1 at scsi2, channel 0, id 0, lun 0
sr1: scsi-1 drive
USB Mass Storage support registered.
========

I checked the kernel sources. Sure enough,
drivers/usb/storage/unusual_devs.h
has a new entry in the 2.6 tree:

========
/* <[email protected]>: I don't know the name of the bridge
* manufacturer, but I've got an external USB drive by the Revoltec company
* that needs this. otherwise the drive is recognized as /dev/sda, but any
* access to it blocks indefinitely.
*/
UNUSUAL_DEV( 0x0402, 0x5621, 0x0103, 0x0103,
"Revoltec",
"USB/IDE Bridge (ATA/ATAPI)",
US_SC_DEVICE, US_PR_DEVICE, NULL, US_FL_FIX_INQUIRY),
========

I have not yet tested after removing this entry, but this looks to be
the likely problem. The enclosure actually supports both 3.5 IDE hard
disks as well as 5.25 CD/DVD drives. I have no clue why this entry
should cause the drive to be wrongly detected. CCing linux-usb-devel for
help.

Please CC me on replies to linux-usb-devel since I am not subscribed to
that list. Thanks.

Ganesan

2004-10-14 14:22:49

by John Stoffel

[permalink] [raw]
Subject: Re: Linux 2.6.x wrongly recognizes USB 2.0 DVD writer


Ganesan> Thanks for the info. As I mentioned, the enclosure works
Ganesan> flawlessly for me under 2.4.27. It's getting detected
Ganesan> incorrectly only in 2.6.x. Another user reported a similar
Ganesan> problem but was able to get dvd burning working by removing
Ganesan> the checks from the writing tool. So, it looks like detection
Ganesan> has been messed up only in 2.6.x.

I'm an idiot. I mis-read your initial post thinking it was like my
ByteCC which has the dual Firewire/USB ports and since I can't get
EITHER interface type to work reliablely, I've given up on it for now.

What's the output of 'lsusb'? You want to see what the vendor/product
ID is as a comparison. I should check mine again under USB and see
what happens under 2.6.8, though earlier it would just hang the entire
system after copying a GB or two of data. At least under FireWire
when it hung, I could recover the system without having to reboot.

Gah... time for more caffeine.

2004-10-14 14:29:54

by Alan Stern

[permalink] [raw]
Subject: Re: [linux-usb-devel] Re: Linux 2.6.x wrongly recognizes USB 2.0 DVD writer

On Thu, 14 Oct 2004, Ganesan R wrote:

> Thanks for the info. As I mentioned, the enclosure works flawlessly for
> me under 2.4.27. It's getting detected incorrectly only in 2.6.x.
> Another user reported a similar problem but was able to get dvd burning
> working by removing the checks from the writing tool. So, it looks like
> detection has been messed up only in 2.6.x.
>
> Once again, 2.6.8 reports it as
>
> ======
> scsi3 : SCSI emulation for USB Mass Storage devices
> Vendor: Revoltec Model: USB/IDE Bridge ( Rev: 0103
> Type: Direct-Access ANSI SCSI revision: 02
> Attached scsi removable disk sdb at scsi3, channel 0, id 0, lun 0
> ======
>
> whereas 2.4.27 correctly reports
>
> ========
> scsi2 : SCSI emulation for USB Mass Storage
> Vendor: _NEC Model: DVD_RW ND-2500A
> Type: CD-ROM ANSI SCSI revision: 02
> Attached scsi CD-ROM sr1 at scsi2, channel 0, id 0, lun 0
> sr1: scsi-1 drive
> USB Mass Storage support registered.
> ========
>
> I checked the kernel sources. Sure enough,
> drivers/usb/storage/unusual_devs.h
> has a new entry in the 2.6 tree:
>
> ========
> /* <[email protected]>: I don't know the name of the bridge
> * manufacturer, but I've got an external USB drive by the Revoltec company
> * that needs this. otherwise the drive is recognized as /dev/sda, but any
> * access to it blocks indefinitely.
> */
> UNUSUAL_DEV( 0x0402, 0x5621, 0x0103, 0x0103,
> "Revoltec",
> "USB/IDE Bridge (ATA/ATAPI)",
> US_SC_DEVICE, US_PR_DEVICE, NULL, US_FL_FIX_INQUIRY),
> ========
>
> I have not yet tested after removing this entry, but this looks to be
> the likely problem. The enclosure actually supports both 3.5 IDE hard
> disks as well as 5.25 CD/DVD drives. I have no clue why this entry
> should cause the drive to be wrongly detected. CCing linux-usb-devel for
> help.

Certainly that entry is the problem. It has been removed in the latest
development kernels; it may already be gone in 2.6.9-rc4.

Alan Stern

2004-10-20 04:56:21

by Ganesan Rajagopal

[permalink] [raw]
Subject: Re: [linux-usb-devel] Re: Linux 2.6.x wrongly recognizes USB 2.0 DVD writer (solved)

On Thu, Oct 14, 2004 at 10:26:53AM -0400, Alan Stern wrote:
>
> On Thu, 14 Oct 2004, Ganesan R wrote:
> >
> > I checked the kernel sources. Sure enough,
> > drivers/usb/storage/unusual_devs.h
> > has a new entry in the 2.6 tree:
> >
> > ========
> > /* <[email protected]>: I don't know the name of the bridge
> > * manufacturer, but I've got an external USB drive by the Revoltec company
> > * that needs this. otherwise the drive is recognized as /dev/sda, but any
> > * access to it blocks indefinitely.
> > */
> > UNUSUAL_DEV( 0x0402, 0x5621, 0x0103, 0x0103,
> > "Revoltec",
> > "USB/IDE Bridge (ATA/ATAPI)",
> > US_SC_DEVICE, US_PR_DEVICE, NULL, US_FL_FIX_INQUIRY),
> > ========
> >
> > I have not yet tested after removing this entry, but this looks to be
> > the likely problem. The enclosure actually supports both 3.5 IDE hard
> > disks as well as 5.25 CD/DVD drives. I have no clue why this entry
> > should cause the drive to be wrongly detected. CCing linux-usb-devel for
> > help.
>
> Certainly that entry is the problem. It has been removed in the latest
> development kernels; it may already be gone in 2.6.9-rc4.

I removed that entry and recompiled 2.6.8. The drive is now recognized
properly again in 2.6.8. Thanks to every one who helped.

Ganesan