RE: Interrupt stom on cardbus device

> -----Original Message-----
> From: Robert Noland [mailto:rnoland_at_FreeBSD.org]
> Sent: Saturday, February 28, 2009 2:44 AM
> To: Nasonov Sergey
> Cc: John Baldwin; freebsd-current_at_freebsd.org
> Subject: RE: Interrupt stom on cardbus device
> 
> On Sat, 2009-02-28 at 00:09 +0300, Nasonov Sergey wrote:
> > > -----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?
> 
> Ok, new patch... It is looking like we should actually deal with this
in
> the pci code, rather than drm, but let's try this patch and see if it
> fixes the issue.  Note that we are looking for interrupts to still
work
> (the msi ones anyway) and to not see the INTx ones.
> 
> http://people.freebsd.org/~rnoland/i915_disable_INTx.patch
> 
> robert.

Unfortunately, your patch doesn't help. Maybe INTx is still enabled? But
I think the problem somewhere herein.
I compile DRM modules with DRM_DEBUG, but output is very large and find
within it anything useful is hard. 
> 
> > 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
> --
> Robert Noland <rnoland_at_FreeBSD.org>
> FreeBSD