Re: [PATCH] ide-cd: fix kernel crash on hppa regression

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Sunday 26 April 2009 08:33:32 Borislav Petkov wrote:
> Hi,
> 
> On Sun, Apr 26, 2009 at 12:51:46AM +0200, Helge Deller wrote:
> ..
> 
> > > Thus please give commit 5ae5412d9a23b05ab08461b202bad21ad8f6b66d ("ide:
> > > add ide_dma_prepare() helper") with your ide-cd fix applied a try.
> > 
> > That is a hard one. Just reverting it (with or without the other one above) prevents
> > me to build a kernel due to compiler errors.

Sorry for not explaining this properly -- I meant doing git checkout at this
commit not reverting it (anyway it isn't needed now as we know that this change
is good since it was done before -rc1).
 
> > Instead I tried 2.6.30-rc1 and 2.6.30-rc2 (all with my simple patch).
> > 2.6.30-rc1 worked without problems.
> > 2.6.30-rc2 did showed the errors.
> > (I should mention, that the cdrom does work even if those messages are printed).
> > The diff of drivers/ide/ns87415.c between those two versions seems unproblematic.
> > Then, after inserting "outb(ATA_DEVCTL_OBS, io_ports->ctl_addr);" to 2.6.30-rc2 didn't fixed it either.
> > 
> > So, I think there is some generic problems in the generic ide cdrom stack, which was
> > introduced between 2.6.30-rc1 and -rc2.
> > 
> > Hope this helps you further.
> 
> Not really, since I'm assuming that it is this particular hardware
> confguration you have that triggers this. It would still be very helpful
> if you'd bisected it since you've narrowed it down to the [30-rc1
> 30-rc2] interval and that isn't going to be a large number of kernel
> compiles :).

Yes, there is only 26 drivers/ide commits in-between, just do:

	git bisect start v2.6.30-rc1 v2.6.30-rc2 drivers/ide

build it, test it, mark it with:

	git bisect bad

or

	git bisect good

and then repeat build-test-mark cycle until the guilty commit is found.

Thanks,
Bart