Re: Status of UDF CD packet writing?

Re: Status of UDF CD packet writing?

[lell02]

>On Tue, Oct 08 2002, lell02 wrote:
>> hi, 
>> 
>> >Will Jens Axboes patch for CD packet writing for CD-R/RW make it in
>> >before the feature freeze? I know Jens Axboe is busy with more basic I/O
>> >stuff, but i sincerely hope it can be squeezed in before 2.6/3.0 is
>> >released.
>> 
>> jens stated on this about 1-2 days ago. he said, it would be little
>> modification on the ide-cdrom, to make it work with cd-mrw/ packet
>> writing.  so it could go in after the feature freeze.
>
>You might be talking about two different patches -- one for cd-rw
>support (this is the pktcdvd (or -packet) patch that Peter Osterlund has
>been maintaining) and the other for cd-mrw. The cd-mrw patch is very
>small, not a lot is required to support that in the cd driver.
>Supporting cd-rw is a lot harder, basically you have to do in software
>what cd-mrw does in hardware (defect management, read-modify-write
>packet gathering, etc).
>
>cd-mrw will definitely be in 2.6. cd-rw support maybe, I haven't even
>looked at that lately.
>

thanx for clearing out these differences. 

but, isn't cd-mrw supposed to replace the old packet-writing technique?
so, in the end, there wouldn't be any need for packet-writing, if every burner 
ships with cd-mrw-support... i read in the "specs", that the technology would 
be much better.



Marcus Lell

Re: Status of UDF CD packet writing?

[Jens Axboe]

On Wed, Oct 09 2002, lell02 wrote:
> >On Tue, Oct 08 2002, lell02 wrote:
> >> hi, 
> >> 
> >> >Will Jens Axboes patch for CD packet writing for CD-R/RW make it in
> >> >before the feature freeze? I know Jens Axboe is busy with more basic I/O
> >> >stuff, but i sincerely hope it can be squeezed in before 2.6/3.0 is
> >> >released.
> >> 
> >> jens stated on this about 1-2 days ago. he said, it would be little
> >> modification on the ide-cdrom, to make it work with cd-mrw/ packet
> >> writing.  so it could go in after the feature freeze.
> >
> >You might be talking about two different patches -- one for cd-rw
> >support (this is the pktcdvd (or -packet) patch that Peter Osterlund has
> >been maintaining) and the other for cd-mrw. The cd-mrw patch is very
> >small, not a lot is required to support that in the cd driver.
> >Supporting cd-rw is a lot harder, basically you have to do in software
> >what cd-mrw does in hardware (defect management, read-modify-write
> >packet gathering, etc).
> >
> >cd-mrw will definitely be in 2.6. cd-rw support maybe, I haven't even
> >looked at that lately.
> >
> 
> thanx for clearing out these differences. 
> 
> but, isn't cd-mrw supposed to replace the old packet-writing
> technique?  so, in the end, there wouldn't be any need for
> packet-writing, if every burner ships with cd-mrw-support... i read in
> the "specs", that the technology would be much better.

(btw, please break your lines at 72 chars or similar)

Yeah that is true, the need for the cd-rw packet writing patch should
diminish once cd-mrw is in all drives.

-- 
Jens Axboe

Re: Status of UDF CD packet writing?

[Brian Gerst]

lell02 wrote:
>>On Tue, Oct 08 2002, lell02 wrote:
>>
>>>hi, 
>>>
>>>
>>>>Will Jens Axboes patch for CD packet writing for CD-R/RW make it in
>>>>before the feature freeze? I know Jens Axboe is busy with more basic I/O
>>>>stuff, but i sincerely hope it can be squeezed in before 2.6/3.0 is
>>>>released.
>>>
>>>jens stated on this about 1-2 days ago. he said, it would be little
>>>modification on the ide-cdrom, to make it work with cd-mrw/ packet
>>>writing.  so it could go in after the feature freeze.
>>
>>You might be talking about two different patches -- one for cd-rw
>>support (this is the pktcdvd (or -packet) patch that Peter Osterlund has
>>been maintaining) and the other for cd-mrw. The cd-mrw patch is very
>>small, not a lot is required to support that in the cd driver.
>>Supporting cd-rw is a lot harder, basically you have to do in software
>>what cd-mrw does in hardware (defect management, read-modify-write
>>packet gathering, etc).
>>
>>cd-mrw will definitely be in 2.6. cd-rw support maybe, I haven't even
>>looked at that lately.
>>
> 
> 
> thanx for clearing out these differences. 
> 
> but, isn't cd-mrw supposed to replace the old packet-writing technique?
> so, in the end, there wouldn't be any need for packet-writing, if every burner 
> ships with cd-mrw-support... i read in the "specs", that the technology would 
> be much better.

For drives that support cd-mrw.  Older cd-rw drives will still need the 
full blown packet writing patch though.

--
				Brian Gerst

Re: Status of UDF CD packet writing?

[Bill Davidsen]

On Wed, 9 Oct 2002, lell02 wrote:

> >You might be talking about two different patches -- one for cd-rw
> >support (this is the pktcdvd (or -packet) patch that Peter Osterlund has
> >been maintaining) and the other for cd-mrw. The cd-mrw patch is very
> >small, not a lot is required to support that in the cd driver.
> >Supporting cd-rw is a lot harder, basically you have to do in software
> >what cd-mrw does in hardware (defect management, read-modify-write
> >packet gathering, etc).
> >
> >cd-mrw will definitely be in 2.6. cd-rw support maybe, I haven't even
> >looked at that lately.
> >
> 
> thanx for clearing out these differences. 
> 
> but, isn't cd-mrw supposed to replace the old packet-writing technique?
> so, in the end, there wouldn't be any need for packet-writing, if every burner 
> ships with cd-mrw-support... i read in the "specs", that the technology would 
> be much better.

When will you be sending me my replacement writers which support cd-mrw?
Hum, I thought not. You ignore the fact that there are at least hundreds
of thousands of devices in use which don't have that feature, but which
will support packet with the existing patches. AFAIK the code exists for
2.4, so perhaps only a port is needed.

Hopefully someone using this can clarify, I tried the code a while ago,
and it worked but was pretty slow. I would still find it useful in many
cases, however, I'm getting smarter about using slow writers :-(

-- 
bill davidsen <davidsen@tmr.com>
  CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.

Re: Status of UDF CD packet writing?

[lell02]

hi, 
>lell02 wrote:
>>>On Tue, Oct 08 2002, lell02 wrote:
>>>
>>>>hi, 
>>>>
>>>>
>>>>>Will Jens Axboes patch for CD packet writing for CD-R/RW make it in
>>>>>before the feature freeze? I know Jens Axboe is busy with more basic I/O
>>>>>stuff, but i sincerely hope it can be squeezed in before 2.6/3.0 is
>>>>>released.
>>>>
>>>>jens stated on this about 1-2 days ago. he said, it would be little
>>>>modification on the ide-cdrom, to make it work with cd-mrw/ packet
>>>>writing.  so it could go in after the feature freeze.
>>>
>>>You might be talking about two different patches -- one for cd-rw
>>>support (this is the pktcdvd (or -packet) patch that Peter Osterlund has
>>>been maintaining) and the other for cd-mrw. The cd-mrw patch is very
>>>small, not a lot is required to support that in the cd driver.
>>>Supporting cd-rw is a lot harder, basically you have to do in software
>>>what cd-mrw does in hardware (defect management, read-modify-write
>>>packet gathering, etc).
>>>
>>>cd-mrw will definitely be in 2.6. cd-rw support maybe, I haven't even
>>>looked at that lately.
>>>
>> 
>> 
>> thanx for clearing out these differences. 
>> 
>> but, isn't cd-mrw supposed to replace the old packet-writing technique?
>> so, in the end, there wouldn't be any need for packet-writing, if every burner 
>> ships with cd-mrw-support... i read in the "specs", that the technology would 
>> be much better.
>
>For drives that support cd-mrw.  Older cd-rw drives will still need the 
>full blown packet writing patch though.

so, both have to go in 2.6/3.0. i hope, they do. it is clear, relying to jens, cd-mrw
is going to be in the future "stable"  kernel, so the question it on pkt-writing...
this code is more than 2 years old (i suppose). so it would be a gain, to include 
it within the official kernel. that would also be a point to the desktop-linux users
to use linux. (that ones dosen't use linux, until it supports things naturely (aka 
in mainline), 'cause they don't believe, it would be stable, until it is in mainline)


Marcus Lell

Re: Status of UDF CD packet writing?

[lell02]

hi, 

>Will Jens Axboes patch for CD packet writing for CD-R/RW make it in
>before the feature freeze? I know Jens Axboe is busy with more basic I/O
>stuff, but i sincerely hope it can be squeezed in before 2.6/3.0 is
>released.

jens stated on this about 1-2 days ago. he said, it would be little modification 
on the ide-cdrom, to make it work with cd-mrw/ packet writing.
so it could go in after the feature freeze.

>
>Most new machines are fitted with a CD burner and some have finally even
>dropped the floppy drive!. Good desktop support is not only about
>low-latency and scheduler issues (Good work though!).
>
>Looking forward to 2.6/3.0 (or whatever the name may be ;-)
>Tommy Vestermark
>

Marcus Lell



>
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Re: Status of UDF CD packet writing?

[Jens Axboe]

On Tue, Oct 08 2002, lell02 wrote:
> hi, 
> 
> >Will Jens Axboes patch for CD packet writing for CD-R/RW make it in
> >before the feature freeze? I know Jens Axboe is busy with more basic I/O
> >stuff, but i sincerely hope it can be squeezed in before 2.6/3.0 is
> >released.
> 
> jens stated on this about 1-2 days ago. he said, it would be little
> modification on the ide-cdrom, to make it work with cd-mrw/ packet
> writing.  so it could go in after the feature freeze.

You might be talking about two different patches -- one for cd-rw
support (this is the pktcdvd (or -packet) patch that Peter Osterlund has
been maintaining) and the other for cd-mrw. The cd-mrw patch is very
small, not a lot is required to support that in the cd driver.
Supporting cd-rw is a lot harder, basically you have to do in software
what cd-mrw does in hardware (defect management, read-modify-write
packet gathering, etc).

cd-mrw will definitely be in 2.6. cd-rw support maybe, I haven't even
looked at that lately.

-- 
Jens Axboe

Status of UDF CD packet writing?

[Tommy Vestermark]

Will Jens Axboes patch for CD packet writing for CD-R/RW make it in
before the feature freeze? I know Jens Axboe is busy with more basic I/O
stuff, but i sincerely hope it can be squeezed in before 2.6/3.0 is
released.

Most new machines are fitted with a CD burner and some have finally even
dropped the floppy drive!. Good desktop support is not only about
low-latency and scheduler issues (Good work though!).

Looking forward to 2.6/3.0 (or whatever the name may be ;-)
Tommy Vestermark