Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Joerg Schilling]

You did write:

>> Executing 'read buffer' command on Bus 1 Target 0, Lun 0 timeout 40s
>> CDB:  3C 00 00 00 00 00 00 FC 00 00
>> 
>> So the kernel doesn't timeout/return for some reason.
>> You can find the full log here:
>> http://muenchen-surf.de/lohmaier/cdrecord_atip_log
>> 
>> If that information is not enough to handle the process, please tell me what
>> else you need. Thank you.
>> 

>We seem to have an awful lot of these "CD burner doesn't work but it did in
>2.4" reports.

>Does anyone have the vaguest inklink of how we broke it?

There are various reasons....

One important problem of course is the fact that various distributors (e.g. 
RedHat, Suse, Debian, Ubuntu) are ungrading cdrecord slower than the Linux 
kernel changes it's interfaces. Related  to is problem: the Linux Kernel folks
do not inform me before breaking Linux kernel interfaces, so I am informed too 
late in order to add a workaround to cdrecord in time.

The most recent interface changes have been:

-	Instead of fixing the bug that allowed anyone to send arbitrary SCSI 
	commands to CD/DVD-recorders (caused by not requiring write permission
	on the node), the behavior of SCSI generic was changed (in 2.6.8.1).

	Old behavior: open device as root and send commands as user.
	New behavior: open device as user and send commands as root.

-	Some time between January 2006 and 2004, a new rlimit "RLIMIT_NOFILE"
	was added and implemented in a way that is not compatible to previous
	kernel behavior.

	Old behavior: mlockall(MCL_CURRENT|MCL_FUTURE) done as root was honored
			for the same process if later continued as user.
	New behavior: mlockall(MCL_CURRENT|MCL_FUTURE) done as root is no longer
			honored for the same process if later continued as user.


Another problem is caused by the fact that various distributors (e.g. RedHat, 
Suse, Debian, Ubuntu) are applying patches to cdrecord that break cdrecord.


The problem mentioned in this thread seems to be caused by the fact that
Linux sometimes ignores timeouts. I have no idea how to help in this (timeout) 
case.



Jörg

-- 
 EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
       js@cs.tu-berlin.de                (uni)  
       schilling@fokus.fraunhofer.de     (work) Blog: http://schily.blogspot.com/
 URL:  http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Andrew Morton]

On Sun, 25 Jun 2006 12:53:55 +0200
Joerg Schilling <schilling@fokus.fraunhofer.de> wrote:

> The problem mentioned in this thread seems to be caused by the fact that
> Linux sometimes ignores timeouts. I have no idea how to help in this (timeout) 
> case.

OK, thanks.  So is that likely to be an IDE bug, or a SCSI bug or an IDE-CD
bug?

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Joerg Schilling]

Andrew Morton <akpm@osdl.org> wrote:

> On Sun, 25 Jun 2006 12:53:55 +0200
> Joerg Schilling <schilling@fokus.fraunhofer.de> wrote:
>
> > The problem mentioned in this thread seems to be caused by the fact that
> > Linux sometimes ignores timeouts. I have no idea how to help in this (timeout) 
> > case.
>
> OK, thanks.  So is that likely to be an IDE bug, or a SCSI bug or an IDE-CD
> bug?

I am not sure if the log from the OP includes all information.

I've seen already messages like this:

cdrecord: Input/output error. Cannot set SG_SET_TIMEOUT.

This should be something that I would never to expect to happen.

If the OP does not see a similar message, it seems that the call is
accepted but later ignored. I have no idea why this happens.

Jörg

-- 
 EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
       js@cs.tu-berlin.de                (uni)  
       schilling@fokus.fraunhofer.de     (work) Blog: http://schily.blogspot.com/
 URL:  http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Joerg Schilling]

Joerg Schilling <schilling@fokus.fraunhofer.de> wrote:

> I am not sure if the log from the OP includes all information.
>
> I've seen already messages like this:
>
> cdrecord: Input/output error. Cannot set SG_SET_TIMEOUT.
>
> This should be something that I would never to expect to happen.
>
> If the OP does not see a similar message, it seems that the call is
> accepted but later ignored. I have no idea why this happens.

Let me add some notes:

Some drives do not support (or correctly support) the 'read buffer' command.
As I don't have all drives, I cannot tell how the drive from the OP behaves on
Solaris. All drives I've seen so far return an error on Solaris - not a timeout,
so it is not clear, whether the hang on Linux would result in a timeout on Solaris.

It may be that the /dev/hd* interface ignores timeouts, but it may also be that
the bus situation did cause a kernel hang. As my experience shows that all 
drives behave always the same, it should be simple to trace the problem for the 
owner of a drive.

Jörg

-- 
 EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
       js@cs.tu-berlin.de                (uni)  
       schilling@fokus.fraunhofer.de     (work) Blog: http://schily.blogspot.com/
 URL:  http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Christian Lohmaier]

On Wed, 28 Jun 2006 09:30:22 +0200, Joerg Schilling wrote:
> Christian Lohmaier wrote:
>>I updated the bug-report with some info I collected from another bug. 
>
>>Apparently my drive sends additional interrupts that confuses the kernel 
>>and make it hang. 
>>The problem is triggered with newer versions of cdrecord (cdrtools 
>>2.01a33 and newer) where cdrecord changed its driver interface. 
> 
> cdrtools-2.01a33 is extremely old (2 years).
> 
> It did not introduce new SCSI commands (compared to prevuious versions) and I
> would be interested why this problem is discussed late.

Because that problems only occurs in the combination of recent cdrtools with
kernel 2.6.x
I for myself have been using kernel 2.4.x until recently I switched to 2.6.x

> The only new thing with cdrecord-2.01a33 is that it started to transfer more 
> than 4 bytes with the "read buffer" command. As this is only issued in case that
> the "read buffer" command did succeed with 4 bytes transfer count and as 
> cdrecord does not transfer more than the drive advertizes, I am just depending 
> on a kernel that does not freeze from the SCSI command I am issuing.

OK - thats already a hint. Maybe this helps the kernel-devs.

ciao
Christian
-- 
NP: Papa Roach - Between Angels And Insects

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Joerg Schilling]

Christian Lohmaier wrote:
>I updated the bug-report with some info I collected from another bug. 

>Apparently my drive sends additional interrupts that confuses the kernel 
>and make it hang. 
>The problem is triggered with newer versions of cdrecord (cdrtools 
>2.01a33 and newer) where cdrecord changed its driver interface. 

cdrtools-2.01a33 is extremely old (2 years).

It did not introduce new SCSI commands (compared to prevuious versions) and I
would be interested why this problem is discussed late.

The only new thing with cdrecord-2.01a33 is that it started to transfer more 
than 4 bytes with the "read buffer" command. As this is only issued in case that
the "read buffer" command did succeed with 4 bytes transfer count and as 
cdrecord does not transfer more than the drive advertizes, I am just depending 
on a kernel that does not freeze from the SCSI command I am issuing.


Jörg

-- 
 EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
       js@cs.tu-berlin.de                (uni)  
       schilling@fokus.fraunhofer.de     (work) Blog: http://schily.blogspot.com/
 URL:  http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Joerg Schilling]

Christian Lohmaier wrote: 
>On Mon, 26 Jun 2006 20:30:19 +0200, Joerg Schilling wrote: 
>> Christian Lohmaier wrote: 
>>>> Why don't you just compile a recent version by your own? 

>>>                 How would I compile the closed-source cdrecord-prodvd 
>>>                 myself? 

>> ???? 

>> are you kidding? 

>No, but you are apparently talking about a totally different thing 
>again. 

>????

You are confusing people here and I am not shure about your intention.....


>> ftp://ftp.berlios.de/pub/cdrecord/aplha/ 

>I cannot find sources for the *proDVD* version there. Yes, I even 
>corrected the typo. 

Is this an attempt tp give wrong information by intention, or are you just
too lazy inform yourself?


>If you mean that the newer alphas are all "proDVD" versions because they 
>now contain dvd-support, you're just confusing people here. 

????

No, it's *you* who is confusing people.


>Even more so because *you already know* that I compiled the new alphas 
>myself. Trying them and having my cdburner not working anymore made me 
>start all this. 

>From your information, it does not look as if you did compile and use
recent versions of cdrecord.

It is obvious that you cannot expect software to work if it triggers
a OS bug.

>By asking such question, assuming "insider" knowledge and despite you 
>already knowing the answer, you're not helping people to focus on the 
>real problem, 

????

Again: you are definitely confusing people and I am not sure whether you 
do this by intention or by mistake.

Jörg

-- 
 EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
       js@cs.tu-berlin.de                (uni)  
       schilling@fokus.fraunhofer.de     (work) Blog: http://schily.blogspot.com/
 URL:  http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Christian Lohmaier]

On Sat, 24 Jun 2006 23:50:07 +0200, Andrew Morton wrote:
> On Sat, 24 Jun 2006 13:36:28 -0700
> bugme-daemon@bugzilla.kernel.org wrote:
> 
>> http://bugzilla.kernel.org/show_bug.cgi?id=6745
>> [...] 
> We seem to have an awful lot of these "CD burner doesn't work but it
> did in
> 2.4" reports.
> 
> Does anyone have the vaguest inklink of how we broke it?

I updated the bug-report with some info I collected from another bug.

Apparently my drive sends additional interrupts that confuses the kernel
and make it hang.
The problem is triggered with newer versions of cdrecord (cdrtools
2.01a33 and newer) where cdrecord changed its driver interface.

So it is only the combination that makes the bug appear.

I hope that with that information it will be possible to fix the kernel
so that it doesn't hang. 

ciao
Christian
-- 
NP: Pantera - Strength Beyond Strength

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Christian Lohmaier]

On Mon, 26 Jun 2006 20:30:19 +0200, Joerg Schilling wrote:
> Christian Lohmaier wrote:
>>> Why don't you just compile a recent version by your own? 
> 
>>                 How would I compile the closed-source cdrecord-prodvd
>>                 myself? 
> 
> ????
> 
> are you kidding?

No, but you are apparently talking about a totally different thing
again.

> ftp://ftp.berlios.de/pub/cdrecord/aplha/

I cannot find sources for the *proDVD* version there. Yes, I even
corrected the typo.

If you mean that the newer alphas are all "proDVD" versions because they
now contain dvd-support, you're just confusing people here.

Even more so because *you already know* that I compiled the new alphas
myself. Trying them and having my cdburner not working anymore made me
start all this.

By asking such question, assuming "insider" knowledge and despite you
already knowing the answer, you're not helping people to focus on the
real problem,

ciao
Christian
-- 
NP: Metallica - Loverman

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Joerg Schilling]

Christian Lohmaier wrote:
>> Why don't you just compile a recent version by your own? 

>                 How would I compile the closed-source cdrecord-prodvd myself? 


????

are you kidding?

ftp://ftp.berlios.de/pub/cdrecord/aplha/

Jörg

-- 
 EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
       js@cs.tu-berlin.de                (uni)  
       schilling@fokus.fraunhofer.de     (work) Blog: http://schily.blogspot.com/
 URL:  http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Christian Lohmaier]

On Sun, 25 Jun 2006 21:50:06 +0200, Joerg Schilling wrote:
>>Since I have a relatively old glibc I cannot use the newer versions of 
>>cdrecord-prodvd, but cdrecord-prodvd-2.01b31-i686-pc-linux-gnu sometimes 
>>works. I did work sometimes, but even when it wors and prints the atip - 
>>compared to using my dvd-recorder it takes ages to print the results. 
> 
> Why don't you just compile a recent version by your own?

How would I compile the closed-source cdrecord-prodvd myself?

ciao
Christian
-- 
NP: Meshuggah - Sublevels

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Joerg Schilling]

>Since I have a relatively old glibc I cannot use the newer versions of 
>cdrecord-prodvd, but cdrecord-prodvd-2.01b31-i686-pc-linux-gnu sometimes 
>works. I did work sometimes, but even when it wors and prints the atip - 
>compared to using my dvd-recorder it takes ages to print the results. 

Why don't you just compile a recent version by your own?

Jörg

-- 
 EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
       js@cs.tu-berlin.de                (uni)  
       schilling@fokus.fraunhofer.de     (work) Blog: http://schily.blogspot.com/
 URL:  http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Christian Lohmaier]

Hi *, thanks for cc'ing me,

On Sun, Jun 25, 2006 at 04:36:22AM -0700, Andrew Morton wrote:
> On Sun, 25 Jun 2006 13:05:59 +0200 (MEST)
> Jan Engelhardt <jengelh@linux01.gwdg.de> wrote:
> 
> > >>            Summary: kernel hangs when trying to read atip wiith cdrecord
> > >>     Kernel Version: 2.6.16.1
> > 
> > >> Most recent kernel where this bug did not occur: 2.6.16.1 (yes, the 
> > >> same version - it works with my dvd-burner, but not with my cd-burner), 
> > >> the 2.4 series worked with both, but there I have been using ide-scsi)
> > 
> > Can you try a newer version and/or (or both) with an original cdrecord (if 
> > not already done so) or cdrecord-prodvd?

I tried with 2.6.17.1, but the problem remains (I use original cdrecord)

Since I have a relatively old glibc I cannot use the newer versions of
cdrecord-prodvd, but cdrecord-prodvd-2.01b31-i686-pc-linux-gnu sometimes
works. I did work sometimes, but even when it wors and prints the atip -
compared to using my dvd-recorder it takes ages to print the results.

But now that I tried to double-check, it hung as well. It printed one
additional line after the supported modes, namely:
Drive buf size : 1806336 = 1764 KB

But then hangs. (full output see below)
 
> > [...]
> > Try -dev=/dev/hdX

That did not make a difference either, apart from the slightly different
warning message at the beginning.

# cdrecord-prodvd-2.01b31-i686-pc-linux-gnu -v dev=ATAPI:1,0,0 -atip
Cdrecord-ProDVD-Clone 2.01b31 (i686-pc-linux-gnu) Copyright (C) 1995-2004 J�rg Schilling
Unlocked features:
Limited  features:
TOC Type: 1 = CD-ROM
scsidev: 'ATAPI:1,0,0'
devname: 'ATAPI'
scsibus: 1 target: 0 lun: 0
Warning: Using ATA Packet interface.
Warning: The related Linux kernel interface code seems to be unmaintained.
Warning: There is absolutely NO DMA, operations thus are slow.
Using libscg version 'schily-0.8'.
SCSI buffer size: 64512
atapi: 1
Device type    : Removable CD-ROM
Version        : 0
Response Format: 1
Vendor_info    : 'CyberDrv'
Identifikation : 'CW058D CD-R/RW  '
Revision       : '160D'
Device seems to be: Generic mmc CD-RW.
Current: Removable Disk
Profile: CD-RW
Profile: CD-R
Profile: CD-ROM
Profile: Removable Disk (current)
Using generic SCSI-3/mmc   CD-R/CD-RW driver (mmc_cdr).
Driver flags   : MMC-2 SWABAUDIO BURNFREE
Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R
Drive buf size : 1806336 = 1764 KB

ciao
Christian
-- 
NP: Limp Bizkit - Re-entry

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Andrew Morton]

On Sun, 25 Jun 2006 13:07:23 +0200
Arjan van de Ven <arjan@infradead.org> wrote:

> On Sat, 2006-06-24 at 14:47 -0700, Andrew Morton wrote:
> > > I simply try to use "cdrecord dev=ATAPI:1,0,0 -atip" as root.
> 
> 
> one issue is that it's a lot better to use --dev=/dev/hda (or whatever
> your cdrom device is.. usually even /dev/cdrom or /dev/cdwriter will
> work, depends on your distro)... that is what most people use and that
> is the interface that's actively supported and debugged...

cc added.

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Andrew Morton]

On Sun, 25 Jun 2006 13:05:59 +0200 (MEST)
Jan Engelhardt <jengelh@linux01.gwdg.de> wrote:

> >>            Summary: kernel hangs when trying to read atip wiith cdrecord
> >>     Kernel Version: 2.6.16.1
> 
> >> Most recent kernel where this bug did not occur: 2.6.16.1 (yes, the 
> >> same version - it works with my dvd-burner, but not with my cd-burner), 
> >> the 2.4 series worked with both, but there I have been using ide-scsi)
> 
> Can you try a newer version and/or (or both) with an original cdrecord (if 
> not already done so) or cdrecord-prodvd?
> 
> >> Distribution: Mandriva 9.0 based
> 
> >> cdrtools 2.01.01a10
> 
> >> Steps to reproduce:
> >> I simply try to use "cdrecord dev=ATAPI:1,0,0 -atip" as root.
> >> # cdrecord dev=ATAPI:1,0,0 -atip
> 
> Try -dev=/dev/hdX
> 

[added Christian (the bug reporter) to cc]

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Arjan van de Ven]

On Sat, 2006-06-24 at 14:47 -0700, Andrew Morton wrote:
> > I simply try to use "cdrecord dev=ATAPI:1,0,0 -atip" as root.


one issue is that it's a lot better to use --dev=/dev/hda (or whatever
your cdrom device is.. usually even /dev/cdrom or /dev/cdwriter will
work, depends on your distro)... that is what most people use and that
is the interface that's actively supported and debugged...

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Jan Engelhardt]

>>            Summary: kernel hangs when trying to read atip wiith cdrecord
>>     Kernel Version: 2.6.16.1

>> Most recent kernel where this bug did not occur: 2.6.16.1 (yes, the 
>> same version - it works with my dvd-burner, but not with my cd-burner), 
>> the 2.4 series worked with both, but there I have been using ide-scsi)

Can you try a newer version and/or (or both) with an original cdrecord (if 
not already done so) or cdrecord-prodvd?

>> Distribution: Mandriva 9.0 based

>> cdrtools 2.01.01a10

>> Steps to reproduce:
>> I simply try to use "cdrecord dev=ATAPI:1,0,0 -atip" as root.
>> # cdrecord dev=ATAPI:1,0,0 -atip

Try -dev=/dev/hdX



Jan Engelhardt
-- 

Re: [Bugme-new] [Bug 6745] New: kernel hangs when trying to read atip wiith cdrecord

[Andrew Morton]

On Sat, 24 Jun 2006 13:36:28 -0700
bugme-daemon@bugzilla.kernel.org wrote:

> http://bugzilla.kernel.org/show_bug.cgi?id=6745
> 
>            Summary: kernel hangs when trying to read atip wiith cdrecord
>     Kernel Version: 2.6.16.1
>             Status: NEW
>           Severity: normal
>              Owner: bzolnier@gmail.com
>          Submitter: lohmaier@gmx.de
> 
> 
> Most recent kernel where this bug did not occur: 2.6.16.1 (yes, the same version
> - it works with my dvd-burner, but not with my cd-burner), the 2.4 series worked
> with both, but there I have been using ide-scsi)
> Distribution: Mandriva 9.0 based
> Hardware Environment:
> cdrom: Cyberdrive CW058D - master on 2nd IDE
> dvd: Pioneer 106D slave on prim. IDE
> MB: elitegroup k7sem with sis chipset (SIS 5513)
> Software Environment:
> cdrtools 2.01.01a10
> 
> Problem Description:
> When trying to use cdrecord with the cdburner, the kernel hangs (not completely,
> only for cd-burning) and the system has to be rebooted. Even retrieving the
> atip-information of a disc fails.
> It fails only with the cd-recorder, not with the DVD-Burner. But when I tried
> with the cdrecorder, burning with the dvd-burner won't work either until the
> machine is rebooted.
> 
> Steps to reproduce:
> I simply try to use "cdrecord dev=ATAPI:1,0,0 -atip" as root.
> # cdrecord dev=ATAPI:1,0,0 -atip
> Cdrecord-ProDVD-Clone 2.01.01a09 (i686-pc-linux-gnu) Copyright (C) 1995-2006
> J�rg Schilling
> cdrecord: Warning: Running on Linux-2.6.16.1
> cdrecord: There are unsettled issues with Linux-2.5 and newer.
> cdrecord: If you have unexpected problems, please try Linux-2.4 or Solaris.
> scsidev: 'ATAPI:1,0,0'
> devname: 'ATAPI'
> scsibus: 1 target: 0 lun: 0
> Warning: Using ATA Packet interface.
> Warning: The related Linux kernel interface code seems to be unmaintained.
> Warning: There is absolutely NO DMA, operations thus are slow.
> Using libscg version 'schily-0.8'.
> Device type    : Removable CD-ROM
> Version        : 0
> Response Format: 1
> Vendor_info    : 'CyberDrv'
> Identifikation : 'CW058D CD-R/RW  '
> Revision       : '160D'
> Device seems to be: Generic mmc CD-RW.
> Using generic SCSI-3/mmc   CD-R/CD-RW driver (mmc_cdr).
> Driver flags   : MMC-2 SWABAUDIO BURNFREE
> Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P
> RAW/R96R
> ----here it hangs and never returns---
> 
> If I run cdrecord with -V (i.e. scsi verbose), it reads:
> [...]
> Executing 'mode select g1' command on Bus 1 Target 0, Lun 0 timeout 40s
> CDB:  55 10 00 00 00 00 00 00 3C 00
> cmd finished after 0.002s timeout 40s
> 
> Executing 'get_configuration' command on Bus 1 Target 0, Lun 0 timeout 40s
> CDB:  46 02 00 37 00 00 00 00 10 00
> cmd finished after 0.000s timeout 40s
> 
> Executing 'read buffer' command on Bus 1 Target 0, Lun 0 timeout 40s
> CDB:  3C 00 00 00 00 00 00 00 04 00
> cmd finished after 0.000s timeout 40s
> 
> Executing 'read buffer' command on Bus 1 Target 0, Lun 0 timeout 40s
> CDB:  3C 00 00 00 00 00 00 FC 00 00
> 
> So the kernel doesn't timeout/return for some reason.
> You can find the full log here:
> http://muenchen-surf.de/lohmaier/cdrecord_atip_log
> 
> If that information is not enough to handle the process, please tell me what
> else you need. Thank you.
> 

We seem to have an awful lot of these "CD burner doesn't work but it did in
2.4" reports.

Does anyone have the vaguest inklink of how we broke it?