Re: [linuxdc-dev]AICA interrupts

[M. R. B. <mr...@0x...>]

* M. R. Brown <mr...@0x...> on Tue, Jan 01, 2002:

> * Adrian McMenamin <ad...@mc...> on Tue, Jan 01, 2002:
>=20
> > I am experimenting with the AICA interrupt - HW_EVENT_AICA_SYS - but I =
am=20
> > getting odd results:
> >=20
> >=20
> [...]
> > When this runs every call to writel(0x20, 0xa07028b8) appears to genera=
te=20
> > "unexpected IRQ trap at vector 0b" (though system output otherwise is n=
ormal).
> >=20
> > What have I done wrong?
> >=20
>=20
> I don't understand why you're getting the "unexpected IRQ ..." message, t=
he
> DC interrupt-handling code switches off of SH4 IRQ's 9, 11, and 13, so th=
ey
> should always be "expected" and return the virtual IRQ.  See
> arch/sh/kernel/setup_dc.c::systemasic_irq_demux() for more info.
>=20

I added the code you sent in your message.

Hmm, ok, I hit it too, but it's still a bit perplexing since
/proc/interrupts says AICA interrupts are being triggered;

# cat /proc/interrupts                                                     =
                                                                           =
   =20
           CPU0                                                            =
                                                                           =
   =20
 16:      11594         IPR-IRQ  timer                                     =
                                                                           =
   =20
 40:          0         IPR-IRQ  sci                                       =
                                                                           =
   =20
 41:        106         IPR-IRQ  sci                                       =
                                                                           =
   =20
 42:          0         IPR-IRQ  sci                                       =
                                                                           =
   =20
 43:        463         IPR-IRQ  sci                                       =
                                                                           =
   =20
 53:       6933     System ASIC  pvr2 VBL handler                          =
                                                                           =
   =20
 81:         32     System ASIC  AICA                                      =
                                                                           =
   =20
 83:       2597     System ASIC  eth0

But I still get the "unexpected IRQ" messages on playback.

I'm going to dig around the irq and DC irq stuff a bit more, I'll let you
know when I find out what's going on.

I'm also starting to suspect something a bit more insidious, after catting
/proc/interrupts a couple of times now I get "Unable to handle kernel
paging request" register dumps, followed by cat segfaulting.  Something
looks to be seriously broken.

M. R.