[linux-dvb] Re: DVB-T crashes Mandrake 9.1

[Philip Armstrong <phil@kantaka.co.uk>]

On Sun, May 04, 2003 at 03:45:51PM +0100, Bruno Prior wrote:
> Philip Armstrong wrote:
> >Linux is perfectly capable of supporting irq sharing. A cursory glance
> >at /proc/interrupts on my machine reveals that the interrupt for my
> >dvb nova-t card is shared with both my ethernet card and my wireless
> >ethernet card for a start.
> 
> So this would seem to indicate that the IRQ-sharing culprit is not the DVB 
> driver, otherwise you would be having problems. Is that a fair conclusion? 
> If so, it suggests the culprit must be the driver for eth0, the other item 
> sharing this interrupt. This is an onboard Gigabit ethernet port, using the 
> e1000 driver.

Merely a suspicion I would say -- I wouldn't got so far as to say
conclusion. I've certainly had trouble with DVB drivers in the past,
but my current drivers (culled from dvb CVS a while ago) have been
completely stable for me.

[snip]
> As above, the same drivers were sharing the same irq previously, and not 
> having problems, so I guess it isn't this.

Seems reasonable.

> >Also, you don't actually say which motherboard you have, but it seems
> >to have an awful lot of unrecognised hardware; I'd have a look on the
> >linux-kernel mailing list to see if there are any reports of problems
> >there. 

It was the unrecognised stuff in the lspci output I was referring to
I think. It was mostly smbus stuff though.

> It's a Gigabyte GA-8PE667 Ultra2. I don't see any unrecognised hardware - 
> only unknown subsystems for the onboard gear. On the face of it, it seems 
> like an excellent board, and was running very happily until the DVB 
> problems. It's based on the Intel 845PE chipset, with 1 AGP and 6 PCI 
> slots. It has support for 4 IDE channels (2 on the Intel chipset, 2 on a 
> Promise PDC20276 controller, that also provides RAID support, which I am 
> not using), and 2 SATA ports, also with RAID support. It has onboard 
> Gigabit ethernet, using the Intel Kenai-32 chipset. You can get most of the 
> rest of the features from the output of lspci in my previous message - 
> basically this board seems to have everything but the kitchen sink. But as 
> I have mentioned previously, this board was running fine until I tried DVB 
> the other day, so I don't think it is anything intrinsically wrong with the 
> board.

Nice board.

[snip Mandrake kernel discussion]

> >One thing which did spring to mind after looking at your logs was that
> >you could try booting with noapic to turn off apic support; if it's
> >the interrupt routing which is being mishandled then turning off the
> >apic support might help.
> 
> This is an excellent idea. I always used to add this to my bootparams (it 
> seems, along with acpi=off and ide=nodma in extremis, to solve a whole host 
> of Mandrake problems), but I have been trying without on the server, to see 
> if it was still required. Until now, I didn't seem to need it - everything 
> was working fine. I have no idea what the APIC does, but if you say it is 
> related to IRQ issues, then this sounds like a good bet. I'll give it a go 
> (and cross my fingers, because everytime I have to hard reset this machine, 
> I have to resync 360Gb of RAID arrays, which is pretty tedious).

Ouch; needing to turn dma off implies real problems with the support
for the motherboard ide chipset. ACPI is more reasonable -- it takes a
while for the acpi suport to catch up with newly released hardware.

APIC == Advanced Programmable Interrupt Controller iirc. If APIC
support is turned off, then linux will use the interrupts setup
programmed by the bios at boottime I believe (so you have to make sure
the bios is setup to fully initialise all your devices at boot if you
turn apic support off in the kernel if I have this right).

Phil

-- 
http://www.kantaka.co.uk/ .oOo. public key: http://www.kantaka.co.uk/gpg.txt


-- 
Info:
To unsubscribe send a mail to ecartis@linuxtv.org with "unsubscribe linux-dvb" as subject.