https://bugzilla.redhat.com/show_bug.cgi?id=311991

[still present in 2.6.23.8]
[Drivers really need to actually be ready to receive interrupts when

they call request_irq(). We keep finding drivers that aren't because

we enable CONFIG_DEBUG_SHIRQ]
kernel version: 2.6.22.7-85.fc7debug

modprobe ioatdma during bootup sez:
[  142.497353] Module ioatdma cannot be unloaded due to unsafe usage in

drivers/dma/ioatdma.c:829

[  142.497906] ACPI: PCI Interrupt 0000:00:08.0[A] -> GSI 16 (level, low) -> IRQ 16

[  142.497945] Unable to handle kernel NULL pointer dereference at

0000000000000003 RIP:

[  142.498002]  [<ffffffff8835adc0>] :ioatdma:ioat_do_interrupt+0xd/0x50

[  142.498770] PGD 10fc46067 PUD 114a56067 PMD 0

[  142.499156] Oops: 0000 [1] SMP

[  142.499498] last sysfs file: /block/sr0/removable

[  142.499753] CPU 3

[  142.500049] Modules linked in: ioatdma dell_rbu nfsd exportfs lockd nfs_acl

ipmi_devintf ipmi_si ipmi_msghandler hidp l2cap bluetooth sunr

pc xt_length ipt_TOS xt_state xt_tcpudp ipt_REJECT ipt_LOG xt_limit

iptable_mangle iptable_nat nf_nat nf_conntrack_ipv4 nf_conntrack nfnetlin

k iptable_filter ip_tables x_tables ppp_deflate zlib_deflate ppp_synctty

ppp_async crc_ccitt ppp_generic slhc bridge dm_mirror dm_multipath d

m_mod video sbs button dock battery ac tcp_westwood kvm_intel kvm sr_mod cdrom

ata_generic ata_piix serio_raw libata bnx2 rtc_cmos sg joydev

usb_storage shpchp megaraid_sas sd_mod scsi_mod ext3 jbd mbcache ehci_hcd

ohci_hcd uhci_hcd

[  142.505129] Pid: 5239, comm: modprobe Not tainted 2.6.22.7-85.fc7debug #1

[  142.505892] RSP: 0018:ffff81010ff83c48  EFLAGS: 00010096

[  142.506146] RAX: 0000000000001214 RBX: 0000000000000202 RCX: ffffffff8835b0f5

[  142.506405] RDX: 0000000000000000 RSI: ffff81012cc11700 RDI: 00000000000008f4

[  142.506663] RBP: ffff81012cc11700 R08: ffff81012cc11700 R09: ffff81012cc11700

[  142.506919] R10: 000000000000005a R11: ffffffff811f2016 R12: 0000000000000020

[  142.507176] R13: ffff81012cc11700 R14: ffffffff8...
[ message continues ]

Chuck - We did some significant rework on the ioatdma driver last

summer.  Unfortunately it didn't make it into 2.6.23, but it is

available in 2.6.24 as well as out-of-core on our SourceForge site.

Please try the newer code - I believe it will fix your problem.
Thanks,

sln

======================================================================

Mr. Shannon Nelson                 LAN Access Division, Intel Corp.

Shannon.Nelson@intel.com                I don't speak for Intel

(503) 712-7659                    Parents can't afford to be squeamish.

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