[pxc] Re: PXC strangeness on Mandriva 2006.0

[M Bianchi]

On Tue, Jul 11, 2006 at 09:10:58AM -0400, M Bianchi wrote:
> On Mon, Jul 10, 2006 at 02:14:37PM -0400, M Bianchi wrote:
> > On Sun, Jul 09, 2006 at 05:32:19PM -0400, M Bianchi wrote:
> > > I've been having trouble bringing up 2  PXC200AL  framegrabbers up on an
> > >  Intel D949GNT  mother board with Celeron 2.53GHz processor under
> > >  Mandriva 2006.0 (kernel 2.6.12-12mdk)  and  pxc-snapshot-051124 .
> > > 	:
> > I still have the problem that the pxc_live and pxc_show applications do not
> > show any image when started after a reboot, BUT do work after
> > 		modprobe bttv
> > 		modprobe -r bttv tvaudio
> > 	:
> Clearly something in the bt878/bttv code is changing the IRQ, but i have not
> yet tried to find it.  Also, without having another means to assign the IRQ
> myself, I am not convinced that the IRQ is what is preventing  pxc.ko  from
> returning data to the applications like  pxc_live .

Found it!

I tried adding a kernel parameter to the  kernel  line in  /boot/grub/menu.lst :
	pci=irqmask=0xFFF0
(This I found in  /usr/src/linux/Documentation/kernel-parameters.txt .)

Did not work.  Then tried:
	pci=irqmask=0x000F

Nope: the cards still came up on IRQs 10 and 9.

I then tried:
	pci=noacpi
Nope.

Then
	pci=routeirq

SUCCESS!  ((Now I know how the Italian football fans feel!))

 lspci -v  reports the IRQs as  21  and  22 , and  pxc_live  is happy.

I don't understand why IRQs 9 and 10 should be a problem, especially since 10
was not shared on my machine, but ...


To summarize:
  In  /boot/grub/menu.lst
	kernel (hd0,0)/vmlinuz-2.6.12-12mdk root=/dev/sda2 pci=routeirq	\
								mem=xxxM

  Somewhere in /etc/rc.d/rc*.d/FILENAME
	./pxc_load buffers=3


Suggestions:
	When no buffers are specified, try 3; report actual memory used.
	If that does not work, complain and try 2;
	No?  Complain and try 1;
	Then fail.
	The assumption that _all_ the unused memory belongs to pxc.ko is not
	reasonable.

	Add comments about IRQs, and  pci=routeirq  to documentation.



Alessandro,
	I'll hack the code and documents if you like.
								Mike

-- 
 Mike Bianchi
 Foveal Systems

 973 822-2085	call to arrange Fax

 MBianchi@Foveal.com
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