RE: Interrupt stom on cardbus device

> -----Original Message-----
> From: John Baldwin [mailto:jhb_at_freebsd.org]
> Sent: Friday, February 27, 2009 10:04 PM
> To: Robert Noland
> Cc: freebsd-current_at_freebsd.org; Nasonov Sergey
> Subject: Re: Interrupt stom on cardbus device
> 
> On Friday 27 February 2009 1:50:28 pm Robert Noland wrote:
> > On Fri, 2009-02-27 at 12:08 -0500, John Baldwin wrote:
> > > On Friday 27 February 2009 9:30:06 am Sergey G Nasonov wrote:
> > > > Hello all,
> > > > I have get an issue after recent kernel recompile.
> > > > The problem appears after switch from X to text console and back
to
> X11.
> > > > After that vmstat -i show an  interrupt storm on cardbus device:
> > > >
> > > > > vmstat -i
> > > > interrupt                          total       rate
> > > > irq1: atkbd0                        6483          3
> > > > irq9: acpi0                         3236          1
> > > > irq12: psm0                       347988        167
> > > > irq14: ata0                        16431          7
> > > > irq16: cbb0 uhci2+              13624982       6556
> > > > irq20: uhci0                          14          0
> > > > irq22: ehci0                           2          0
> > > > cpu0: timer                      4154687       1999
> > > > irq256: em0                        53736         25
> > > > irq257: hdac0                       5797          2
> > > > cpu1: timer                      4153683       1998
> > > > irq258: vgapci0                   235585        113
> > > > Total                           22602624      10877
> > > >
> > > > I suppose that the issue related with the latest MSI interrupt
> > > > handler changes for intel graphics chipset. My laptop has
i965GM.
> > > > pciconf -lv:
> > > >
> > > > vgapci0_at_pci0:0:2:0:     class=0x030000 card=0x20b517aa
> chip=0x2a028086
> > > > rev=0x0c hdr=0x00
> > > >     vendor     = 'Intel Corporation'
> > > >     device     = 'Mobile 965 Express Integrated Graphics
Controller'
> > > >     class      = display
> > > >     subclass   = VGA
> > > >
> > > > When I added my device to drm_msi_blacklist and recompile drm
> modules
> the
> > > > problem disappear.
> > > > Is it possible to resolve this problem without moving the device
to
> the
> > > > drm_msi_blacklist?
> > > > I can test any patches or provide additional detail if it is
> required.
> > > > Thanks.
> > >
> > > It seems the device is still interrupting on its INTx line perhaps
in
> addition
> > > to the MSI interrupts.
> >
> > Hrm, I did most all of that development on a 965gm.  When you VT
switch,
> > the irq handler gets uninstalled and reinstalled when you return to
X.
> > There was an eratta on the 965gm suggesting that msi didn't work
right,
> > but I was never able to produce the issue.  Intel was having major
> > issues with this on linux and I finally convinced them to turn msi
back
> > on.  My irq handler and Eric's are very similar, so I'm not sure
what
> > could be going on here.
> >
> > There is however an issue with vblanks that might be related.  Could
you
> > try http://people.freebsd.org/~rnoland/drm-move_vblank_init.patch
and
> > see if that helps?

Ok, I tried it but result the same (problem not resolved).
Can I check anything else?
Thanks.
> 
> In this case the issue isn't that MSI isn't working I think, but that
the
> hardware is sending interrupts via both routes (MSI and INTx).  If
that
> happens, then you will see an interrupt storm on the INTx line, but
> FreeBSD
> will only notice if another device is sharing the same IRQ line.  So
if
> your
> test machine has vgapci0 on irq 22 and you have no other devices on
IRQ
> 22,
> then the storm would go unnoticed.  This is most likely a chip bug
(unless
> the driver has to explicitly disable INTx interrupts when using MSI).
It
> would probably be a good idea to add a hw.drm.msi_enable tunable (or
> hw.drm.msi) that people can use to disable MSI perhaps.
> 
> --
> John Baldwin