Re: [PATCH] [broken?] Add MSI support to e1000

[Roland Dreier <roland@topspin.com>]

    Tom> Agree. The question is that how many egde-triggered MSI with
    Tom> the same vector are generated by e1000 hardware when its
    Tom> service handler is still running.

One piece of information that I just noticed is that all of my tests
were done with CONFIG_E1000_NAPI turned on, so I may be hitting some
NAPI race condition.  Unfortunately I can't try anything on my Dell P4
system (I don't have remote serial access and I'm not in front of the
machine, so I can't mess with the network driver).

I did do a little more testing on the dual Nocona/Lindenhurst system
that I do have remote serial access to (lspci at the end of this
email).  In my earlier testing I only looked at "ifconfig" and
"/proc/interrupts" information -- what I didn't notice was that
networking didn't work at all (and tcpdump shows no packets being
received).  This happens even with NAPI turned off.

I added a little more debugging to the driver and it seems that it
reads a bogus RX descriptor (status == 0x63, errors == 0x6f).  This
happens exactly when MSI is turned on, although I have no idea why.

Unfortunately I'm afraid that I may be running into some Nocona or
Lindenhurst errata on this system.  I'll be able to try my P4 system
(with 865 chipset) tomorrow.

One other thing I don't understand independent of any e1000 issues I'm
running into is what could cause this type of message:

    CPU 0: Machine Check Exception: 0000000000000000
    CPU 0: EIP: 00000000 EFLAGS: 00000000
            eax: 00000000 ebx: 00000000 ecx: 00000000 edx: 00000000
            esi: 00000000 edi: 00000000 ebp: 00000000 esp: 00000000

The "0000000000000000" above is coming from the IA32_MCG_STATUS MSR,
and it seems to show a machine check occurring with MCIP ("machine
check in progress") == 0 -- any idea how this could happen?

Thanks,
  Roland

0000:00:00.0 Host bridge: Intel Corp. Server Memory Controller Hub (rev 09)
0000:00:00.1 ff00: Intel Corp. Memory Controller Hub Error Reporting Register (rev 09)
0000:00:01.0 System peripheral: Intel Corp. Memory Controller Hub DMA Controller (rev 09)
0000:00:02.0 PCI bridge: Intel Corp. Memory Controller Hub PCI Express Port A0 (rev 09)
0000:00:04.0 PCI bridge: Intel Corp. Memory Controller Hub PCI Express Port B0 (rev 09)
0000:00:05.0 PCI bridge: Intel Corp. Memory Controller Hub PCI Express Port B1 (rev 09)
0000:00:06.0 PCI bridge: Intel Corp. Memory Controller Hub PCI Express Port C0 (rev 09)
0000:00:07.0 PCI bridge: Intel Corp. Memory Controller Hub PCI Express Port C1 (rev 09)
0000:00:08.0 System peripheral: Intel Corp. Memory Controller Hub Extended Configuration Registers (rev 09)
0000:00:1d.0 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #1 (rev 02)
0000:00:1d.1 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #2 (rev 02)
0000:00:1d.2 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #3 (rev 02)
0000:00:1d.7 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB2 EHCI Controller (rev 02)
0000:00:1e.0 PCI bridge: Intel Corp. 82801 PCI Bridge (rev c2)
0000:00:1f.0 ISA bridge: Intel Corp. 82801EB/ER (ICH5/ICH5R) LPC Bridge (rev 02)
0000:00:1f.2 IDE interface: Intel Corp. 82801EB (ICH5) Serial ATA 150 Storage Controller (rev 02)
0000:00:1f.3 SMBus: Intel Corp. 82801EB/ER (ICH5/ICH5R) SMBus Controller (rev 02)
0000:01:02.0 VGA compatible controller: ATI Technologies Inc Rage XL (rev 27)
0000:02:00.0 PCI bridge: Intel Corp. PCI Bridge Hub A (rev 09)
0000:02:00.1 PIC: Intel Corp. PCI Bridge Hub I/OxAPIC Interrupt Controller A (rev 09)
0000:02:00.2 PCI bridge: Intel Corp. PCI Bridge Hub B (rev 09)
0000:02:00.3 PIC: Intel Corp. PCI Bridge Hub I/OxAPIC Interrupt Controller B (rev 09)
0000:04:01.0 Ethernet controller: Intel Corp. 82545EM Gigabit Ethernet Controller (Copper) (rev 01)
0000:04:03.0 SCSI storage controller: Adaptec AIC-7902 U320 (rev 03)
0000:04:03.1 SCSI storage controller: Adaptec AIC-7902 U320 (rev 03)
0000:07:00.0 InfiniBand: Mellanox Technology: Unknown device 6278 (rev a0)

detailed lspci of e1000:

0000:04:01.0 Ethernet controller: Intel Corp. 82545EM Gigabit Ethernet Controller (Copper) (rev 01)
	Subsystem: Intel Corp. PRO/1000 MT Server Adapter
	Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 209
	Memory at fe2c0000 (64-bit, non-prefetchable) [size=128K]
	I/O ports at d480 [size=64]
	Capabilities: [dc] Power Management version 2
	Capabilities: [e4] PCI-X non-bridge device.
	Capabilities: [f0] Message Signalled Interrupts: 64bit+ Queue=0/0 Enable-
00: 86 80 0f 10 17 01 30 02 01 00 00 02 10 40 00 00
10: 04 00 2c fe 00 00 00 00 00 00 00 00 00 00 00 00
20: 81 d4 00 00 00 00 00 00 00 00 00 00 86 80 01 10
30: 00 00 00 00 dc 00 00 00 00 00 00 00 0b 01 ff 00
40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 01 e4 22 00
e0: 00 00 00 00 07 f0 02 00 08 04 43 04 00 00 00 00
f0: 05 00 80 00 04 10 e0 fe 00 00 00 00 32 40 00 00