Missing SCSI command in the allowed list?

Missing SCSI command in the allowed list?

[Alexander E. Patrakov]

While cloning an audio CD using cdrdao 1.1.9 with vanilla linux-2.6.9 as a
user, I see the following "errors":

ERROR: Read buffer capacity failed.

This refers to the buffer in the CD drive. The indiation of the drive buffer
fill is missing. The clone sounds like the original. The command used for
cloning:

cdrdao copy --device /dev/hdd --source-device /dev/hdb \
--drivergeneric-mmc-raw --speed 8 --on-the-fly --paranoia-mode 1 -v 1 \
--fast-toc

If I run that as root, there are no such "errors", and levels of both the
software cdrdao buffer and hardware buffer in the drive are indicated.

Looks like the following SCSI command is missing from the allowed list:

cmd[0] = 0x5c; // READ BUFFER CAPACITY

(according to cdrdao source, Sony CDU920 uses 0xec instead, but I don't have
Sony drives here). Please fix the list or explain why this cannot be done.

-- 
Alexander E. Patrakov

Re: Missing SCSI command in the allowed list?

[Daniel Drake]

Hi,

On Saturday 06 November 2004 13:47, Alexander E. Patrakov wrote:
> While cloning an audio CD using cdrdao 1.1.9 with vanilla linux-2.6.9 as a
> user, I see the following "errors":
>
> ERROR: Read buffer capacity failed.

I submitted a patch for this a few days ago. It has been merged into Linus's 
tree.

Daniel

Re: Missing SCSI command in the allowed list?

[Alexander E. Patrakov]

Daniel Drake wrote:

> Hi,
> 
> On Saturday 06 November 2004 13:47, Alexander E. Patrakov wrote:
>> While cloning an audio CD using cdrdao 1.1.9 with vanilla linux-2.6.9 as
>> a user, I see the following "errors":
>>
>> ERROR: Read buffer capacity failed.
> 
> I submitted a patch for this a few days ago. It has been merged into
> Linus's tree.

Yes, I see the patch, thanks:

http://www.kernel.org/pub/linux/kernel/v2.6/testing/cset/cset-axboe%40suse.de[torvalds]
ChangeSet|20041104154725|45958.txt

But the question remains: what should the users of not 100% MMC-compatible
CR-RW drives (i.e. those which have a separate cdrado or cdrecord driver,
not generic-mmc/generic-mmc-raw) do? Is the support for writing as non-root
on such drives just dropped without any plans to "fix" it?

-- 
Alexander E. Patrakov

Re: Missing SCSI command in the allowed list?

[Daniel Drake]

Hi,

Alexander E. Patrakov wrote:
> But the question remains: what should the users of not 100% MMC-compatible
> CR-RW drives (i.e. those which have a separate cdrado or cdrecord driver,
> not generic-mmc/generic-mmc-raw) do? Is the support for writing as non-root
> on such drives just dropped without any plans to "fix" it?

I'd also be interested to know the answer here. Jens?

Some Gentoo users have reported that commands such as ED/EB/E9/F5 are being 
rejected. When inspecting the cdrecord source code, it seems that these are 
specific to plextor drives. These drives are MMC but have a few 
vendor-specific extensions. How should we go about permitting cases like this 
in the command filter?

Thanks,
Daniel

Re: Missing SCSI command in the allowed list?

[Alan Cox]

On Iau, 2004-11-18 at 18:39, Daniel Drake wrote:
> Some Gentoo users have reported that commands such as ED/EB/E9/F5 are being 
> rejected. When inspecting the cdrecord source code, it seems that these are 
> specific to plextor drives. These drives are MMC but have a few 
> vendor-specific extensions. How should we go about permitting cases like this 
> in the command filter?

Someone posted a very nice patch that added a little fs so you could
adjust the tables from user space. I'd suggest that. Unfortunately its
not been merged with the base kernel yet

Re: Missing SCSI command in the allowed list?

[Jens Axboe]

On Thu, Nov 18 2004, Daniel Drake wrote:
> Hi,
> 
> Alexander E. Patrakov wrote:
> >But the question remains: what should the users of not 100% MMC-compatible
> >CR-RW drives (i.e. those which have a separate cdrado or cdrecord driver,
> >not generic-mmc/generic-mmc-raw) do? Is the support for writing as non-root
> >on such drives just dropped without any plans to "fix" it?
> 
> I'd also be interested to know the answer here. Jens?
> 
> Some Gentoo users have reported that commands such as ED/EB/E9/F5 are being 
> rejected. When inspecting the cdrecord source code, it seems that these are 
> specific to plextor drives. These drives are MMC but have a few 
> vendor-specific extensions. How should we go about permitting cases like 
> this in the command filter?

See Alans post, that's the only real way to deal with the situation.
Right now we are stuck with half a solution (which is better than none
or the 5% initial solution), it would still be nice to have it finished.
Search the archives, there were several posts on this.

-- 
Jens Axboe