[mythtv-users] OT? /proc/pci

[Sean Covel]

That's probably it.  The mobo of my backend box is OLD.  Its running 2 
PIII 600Mhz Slot 1 procs and the on-board IDE is only UDMA33.  OLD!  My 
"play" machine is running 2 PIII 1.2Mhz Server procs.  Guess its time to 
swap the backend to the "play" machine.

Tim Tait wrote:
> Jason Kraftcheck wrote:
> 
>>Joel Anderson wrote:
>>  
>>
>>>Marc-David Meijer wrote:
>>>
>>>As I understand it, PCI devices don't depend on IRQs anyway.  They use
>>>interrupt "channels", and IRQs are just kept around to keep legacy stuff
>>>happy.  You will often see many devices appear to "share" the same IRQ,
>>>but it is not really true since IRQ's can't really _be_ shared.
>>>
>>>Someone please comment if I haven't explained this correctly.  It's a
>>>simplification, but it basically means that IRQ issues shouldn't come
>>>into play unless you have some legacy hardware in the system also.
>>>    
>>>
>>
>>I'm no expert either, but I think they are actually "shared".  The
>>interrupt handler must poll each device by invoking the interrupt
>>handler in the driver for each device sharing the interrupt.  Thus
>>there's a slight performance loss when sharing interrupts, and also the
>>possibility for buggy drivers to interfere with each other.
>>  
>>
> Newer PCI devices support "Message Signalled Interrupts" which use no 
> physical IRQ line, but instead write a pre-configured value to the PCI 
> bridge inbound MSI register to cause a unique interrupt. I can't say for 
> sure the 250MCE actually does that (or that the driver sets it up that 
> way) but it is possible.  People have commented eslwhere on the list 
> that it appears the 250MCE needs a PCI Rev 2.2 compliant motherboard, so 
> you might want to check your  mobo docs out and see if it complies.
> 

Tim,

That's probably it.  The mobo of my backend box is OLD.  Its running 2 
PIII 600Mhz Slot 1 procs and the on-board IDE is only UDMA33.  OLD!  My 
"play" machine is running 2 PIII 1.2Mhz Server procs.  Guess its time to 
swap the MythTv backend to the "play" machine.

The "play" machine does recognize the card, now I need to spend the time 
to get IVTV working on it.  I'm sure it will work now that lspci 
recognizes the card.

Thanks for all your help guys!!!

Sean