Date: Fri, 27 Feb 2009 14:03:46 -0500 From: John Baldwin <jhb@freebsd.org> To: Robert Noland <rnoland@freebsd.org> Cc: freebsd-current@freebsd.org, Sergey G Nasonov <snasonov@bcc.ru> Subject: Re: Interrupt stom on cardbus device Message-ID: <200902271403.46828.jhb@freebsd.org> In-Reply-To: <1235760629.1289.51.camel@widget.2hip.net> References: <200902271730.07660.snasonov@bcc.ru> <200902271208.48212.jhb@freebsd.org> <1235760629.1289.51.camel@widget.2hip.net>
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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@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? 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
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