Re: [BUG] 2.6.25-rc2-git3 broke cdrecord

["Carlos R. Mafra" <crmafra2@gmail.com>]

On Sun  2.Mar'08 at 21:53:25 +0100, Mikael Pettersson wrote:
> On my main workstation (Intel P965 chipset, ICH8 SATA driven by ahci,
> Samsung/Toshiba SH-203P SATA DVD writer, FC5 user-space), cdrecord
> stopped working on the 2.6.25-rc3 kernel, with the complaint:
> 
> Warning: controller returns zero sized CD capabilities page.
> Warning: controller returns wrong page 0 for CD capabilities page (2A).
> 
> There's nothing in dmesg to suggest that the kernel has experienced
> some problem.
> 
> 2.6.25-rc2-git2 was the last working kernel, 2.6.25-rc2-git3 up to
> today's 2.6.25-rc3-git3 are all non-working.
> 
> I've narrowed the cause down to these two commits in 2.6.25-rc2-git3:
> 
> 40b01b9bbdf51ae543a04744283bf2d56c4a6afa
> block: update bio according to DMA alignment padding
> 
> 6b00769fe1502b4ad97bb327ef7ac971b208bfb5
> block: add request->raw_data_len
> 
> Four or so subsequent commits depend on the second of these, so it's
> easier to test them by applying them to -git2 than to revert them.
> 
> Also, these two need to be treated as a unit. With only the first
> applied, I get a massive delay as init tries to start udev, and then
> if I try cdrecord it hangs in an unkillable state.
> 
> I've put some information in
> <http://user.it.uu.se/~mikpe/linux/bug-2.6.25-rc3-cdrecord/>:
> - the kernel's .config
> - cdrecord -VV dev=/dev/scd0 blank=fast output for 2.6.25-rc2-git2 and -git3
> - strace -v logs for the above cdrecord runs

I will try to help by pointing you to the patch here: 
http://lkml.org/lkml/2008/2/28/76

It seems your problem is similar to the one Mike Galbraith reported.