[PATCH] DVD-RAM rewritable again

[PATCH] DVD-RAM rewritable again

[Pat LaVarre]

Jens A:

Can I help by offering the trivial patch shown here?  Or can I help in
some other way?

I ask because I see this patch makes my PATAPI DVD-RAM disc as
rewritable as it was in 2.4.26.

Per my understanding of your instructions, I defer, until 2.4.28, the
non-trivial work of making PATAPI and USB DVD-RAM discs behave the same.

Per my understanding of your instructions, I leave USB DVD-RAM discs not
rewritable until 2.4.28, since those discs have not been rewritable at
least since 2.4.26.

Pat LaVarre

diff -urp linux-2.4.27-rc4/drivers/cdrom/cdrom.c linux-2.4.27-rc4-pel/drivers/cdrom/cdrom.c
--- linux-2.4.27-rc4/drivers/cdrom/cdrom.c	2004-08-01 08:50:45.000000000 -0600
+++ linux-2.4.27-rc4-pel/drivers/cdrom/cdrom.c	2004-08-03 15:10:48.048576912 -0600
@@ -536,6 +536,8 @@ static int cdrom_open_write(struct cdrom
 	if (CDROM_CAN(CDC_RAM) &&
 	    !CDROM_CAN(CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R)) 
 		ret = cdrom_ram_open_write(cdi);
+	else if (CDROM_CAN(CDC_DVD_RAM))
+		ret = 0;
 	else
 		ret = 1;

Re: [PATCH] DVD-RAM rewritable again

[Jens Axboe]

On Tue, Aug 03 2004, Pat LaVarre wrote:
> Jens A:
> 
> Can I help by offering the trivial patch shown here?  Or can I help in
> some other way?
> 
> I ask because I see this patch makes my PATAPI DVD-RAM disc as
> rewritable as it was in 2.4.26.
> 
> Per my understanding of your instructions, I defer, until 2.4.28, the
> non-trivial work of making PATAPI and USB DVD-RAM discs behave the same.
> 
> Per my understanding of your instructions, I leave USB DVD-RAM discs not
> rewritable until 2.4.28, since those discs have not been rewritable at
> least since 2.4.26.
> 
> Pat LaVarre
> 
> diff -urp linux-2.4.27-rc4/drivers/cdrom/cdrom.c linux-2.4.27-rc4-pel/drivers/cdrom/cdrom.c
> --- linux-2.4.27-rc4/drivers/cdrom/cdrom.c	2004-08-01 08:50:45.000000000 -0600
> +++ linux-2.4.27-rc4-pel/drivers/cdrom/cdrom.c	2004-08-03 15:10:48.048576912 -0600
> @@ -536,6 +536,8 @@ static int cdrom_open_write(struct cdrom
>  	if (CDROM_CAN(CDC_RAM) &&
>  	    !CDROM_CAN(CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R)) 
>  		ret = cdrom_ram_open_write(cdi);
> +	else if (CDROM_CAN(CDC_DVD_RAM))
> +		ret = 0;
>  	else
>  		ret = 1;

That looks fine!

-- 
Jens Axboe

Re: [PATCH] DVD-RAM rewritable again

[Pat LaVarre]

> > @@ -536,6 +536,8 @@ static int cdrom_open_write(struct cdrom
> >  	if (CDROM_CAN(CDC_RAM) &&
> >  	    !CDROM_CAN(CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R)) 
> >  		ret = cdrom_ram_open_write(cdi);
> > +	else if (CDROM_CAN(CDC_DVD_RAM))
> > +		ret = 0;
> ...
> That looks fine!

Good to hear, I was not certain.

Can I/ should I do anything more to help, ... before we begin the 2.4.28
work of making USB DVD-RAM discs also rewritable, same as USB Iomega REV
discs?

Pat LaVarre

P.S. I notice kernel.org changing in parallel with this thread:

--- http://www.kernel.org/pub/linux/kernel/v2.4/testing/patch-2.4.27.log
...
Summary of changes from v2.4.27-rc4 to v2.4.27-rc5
...
Marcelo Tosatti:
  o Revert DVD-RW write support for now: axboe@suse.de|ChangeSet|20040606235035|46544
  o Cset exclude: axboe@suse.de|ChangeSet|20040607195639|57919
...
---

Me the kernelnewbie, I don't yet know how to click thru to a ChangeSet
to see specifically what these summaries mean.

Re: [PATCH] DVD-RAM rewritable again

[Jens Axboe]

On Wed, Aug 04 2004, Pat LaVarre wrote:
> > > @@ -536,6 +536,8 @@ static int cdrom_open_write(struct cdrom
> > >  	if (CDROM_CAN(CDC_RAM) &&
> > >  	    !CDROM_CAN(CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R)) 
> > >  		ret = cdrom_ram_open_write(cdi);
> > > +	else if (CDROM_CAN(CDC_DVD_RAM))
> > > +		ret = 0;
> > ...
> > That looks fine!
> 
> Good to hear, I was not certain.
> 
> Can I/ should I do anything more to help, ... before we begin the 2.4.28
> work of making USB DVD-RAM discs also rewritable, same as USB Iomega REV
> discs?

Prepare a patch against current 2.4.27-rc5 with everything, test it, and
then we can send it to Marcelo when 2.4.28 opens.

-- 
Jens Axboe

Re: [PATCH] DVD-RAM rewritable again

[Marcelo Tosatti]

On Wed, Aug 04, 2004 at 05:35:47AM -0600, Pat LaVarre wrote:
> > > @@ -536,6 +536,8 @@ static int cdrom_open_write(struct cdrom
> > >  	if (CDROM_CAN(CDC_RAM) &&
> > >  	    !CDROM_CAN(CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R)) 
> > >  		ret = cdrom_ram_open_write(cdi);
> > > +	else if (CDROM_CAN(CDC_DVD_RAM))
> > > +		ret = 0;
> > ...
> > That looks fine!
> 
> Good to hear, I was not certain.
> 
> Can I/ should I do anything more to help, ... before we begin the 2.4.28
> work of making USB DVD-RAM discs also rewritable, same as USB Iomega REV
> discs?
> 
> Pat LaVarre
> 
> P.S. I notice kernel.org changing in parallel with this thread:
> 
> --- http://www.kernel.org/pub/linux/kernel/v2.4/testing/patch-2.4.27.log
> ...
> Summary of changes from v2.4.27-rc4 to v2.4.27-rc5
> ...
> Marcelo Tosatti:
>   o Revert DVD-RW write support for now: axboe@suse.de|ChangeSet|20040606235035|46544
>   o Cset exclude: axboe@suse.de|ChangeSet|20040607195639|57919
> ...
> ---
> 
> Me the kernelnewbie, I don't yet know how to click thru to a ChangeSet
> to see specifically what these summaries mean.

Go to http://linux.bkbits.net/linux-2.4 then you can easily see the changesets... 

dvd-ram open succeeds despite write-protect

[Pat LaVarre]

Jens A:

> Subject: Re: [PATCH] DVD-RAM rewritable again
> ...
> ... with everything, test ...

In 2.6 Linux, do we care about write-protected DVD/CD discs?  Do we
agree they don't quite work yet?  Can I help best by working to fix
them?

Just now I specifically tried toggling the invisible MMC PWP
write-protect switch found inside of DVD-RAM discs, Iomega REV discs,
etc.  In Linux-2.6.8.1, with write-protected discs,

I'm glad to see EROFS correctly fail open to write of Iomega REV discs,
no matter PATAPI or USB.  But I'm sorry to see open, write, and close of
DVD-RAM discs succeed, no matter PATAPI or USB.  Only in my dmesg do I
see that the DVD-RAM disc is actually not changing, e.g.

kernel: hdd: command error: status=0x51 { DriveReady SeekComplete Error }
kernel: hdd: command error: error=0x70
kernel: end_request: I/O error, dev hdd, sector 0

kernel: SCSI error : <0 0 0 0> return code = 0x8000002
kernel: Current sr0: sense key Data Protect
kernel: Additional sense: Write protected
kernel: end_request: I/O error, dev sr0, sector 0

Pat LaVarre
http://linux-pel.blog-city.com/read/771746.htm

Re: [PATCH] DVD-RAM rewritable again

[Pat LaVarre]

> Go to http://linux.bkbits.net/linux-2.4
> then you can easily see the changesets...

Yes, thank you, I found:

http://linux.bkbits.net:8080/linux-2.4

And then:

http://linux.bkbits.net:8080/linux-2.4/gnupatch@410e3186Ls2xs-p-21YhVWn-m0byNw
http://linux.bkbits.net:8080/linux-2.4/gnupatch@40c3adcb7pPfs09Pc46DvR2DTq6v5g
http://linux.bkbits.net:8080/linux-2.4/gnupatch@410e91ddoZNIQrI8VWJjHKxro-BH7w
http://linux.bkbits.net:8080/linux-2.4/gnupatch@40c4c87778sEsIcHpeYmVIOFfCtwNQ 
Pat LaVarre