2.6.16.13 e1000 reports incorrect PCI-X bus speed?

DISCUSSION Ben Greear 4 participants 5 messages May 12, 2006 – May 14, 2006

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Ben Greear

author

2006-05-12 21:15 UTC #0 lore raw

I'm running a slightly modified 2.6.16.13 kernel on FC5-amd64. The motherboard is SuperMicro H8SSL dual-core AMD system. According to super-micro web site, the PCI-X slot is 133Mhz. I'm using a 4-port pro/1000 NIC.

dmesg shows a listing of 120Mhz:

Intel(R) PRO/1000 Network Driver - version 6.3.9-k4-NAPI Copyright (c) 1999-2005 Intel Corporation.
GSI 18 sharing vector 0xB9 and IRQ 18
ACPI: PCI Interrupt 0000:03:04.0[A] -> GSI 20 (level, low) -> IRQ 18
e1000: 0000:03:04.0: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:bc
e1000: eth2: e1000_probe: Intel(R) PRO/1000 Network Connection GSI 19 sharing vector 0xC1 and IRQ 19
ACPI: PCI Interrupt 0000:03:04.1[B] -> GSI 21 (level, low) -> IRQ 19
e1000: 0000:03:04.1: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:bd
e1000: eth3: e1000_probe: Intel(R) PRO/1000 Network Connection GSI 20 sharing vector 0xC9 and IRQ 20
ACPI: PCI Interrupt 0000:03:06.0[A] -> GSI 22 (level, low) -> IRQ 20
e1000: 0000:03:06.0: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:be
e1000: eth4: e1000_probe: Intel(R) PRO/1000 Network Connection GSI 21 sharing vector 0xD1 and IRQ 21
ACPI: PCI Interrupt 0000:03:06.1[B] -> GSI 23 (level, low) -> IRQ 21
e1000: 0000:03:06.1: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:bf
e1000: eth5: e1000_probe: Intel(R) PRO/1000 Network Connection

ethtool -d eth3 shows 66Mhz:
....
0x00008: STATUS (Device status register) 0x00003B87

      Duplex:                            full
      Link up:                           link config
      TBI mode:                          disabled
      Link speed:                        1000Mb/s
      Bus type:                          PCI-X
      Bus speed:                         66MHz
      Bus width:                         64-bit

Any idea why I see the slower bus speed reported?

More info available as needed.

Thanks,
Ben

Signature · 2 lines

Ben Greear <[email protected]>
Candela Technologies Inc  http://www.candelatech.com

Auke Kok

2006-05-12 21:33 UTC #1 lore raw

Quoted 36 lines · Ben Greear

I'm running a slightly modified 2.6.16.13 kernel on FC5-amd64. The motherboard is SuperMicro H8SSL dual-core AMD system. According to super-micro web site, the PCI-X slot is 133Mhz. I'm using a 4-port pro/1000 NIC.
dmesg shows a listing of 120Mhz:
Intel(R) PRO/1000 Network Driver - version 6.3.9-k4-NAPI Copyright (c) 1999-2005 Intel Corporation.
GSI 18 sharing vector 0xB9 and IRQ 18
ACPI: PCI Interrupt 0000:03:04.0[A] -> GSI 20 (level, low) -> IRQ 18
e1000: 0000:03:04.0: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:bc
e1000: eth2: e1000_probe: Intel(R) PRO/1000 Network Connection GSI 19 sharing vector 0xC1 and IRQ 19
ACPI: PCI Interrupt 0000:03:04.1[B] -> GSI 21 (level, low) -> IRQ 19
e1000: 0000:03:04.1: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:bd
e1000: eth3: e1000_probe: Intel(R) PRO/1000 Network Connection GSI 20 sharing vector 0xC9 and IRQ 20
ACPI: PCI Interrupt 0000:03:06.0[A] -> GSI 22 (level, low) -> IRQ 20
e1000: 0000:03:06.0: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:be
e1000: eth4: e1000_probe: Intel(R) PRO/1000 Network Connection GSI 21 sharing vector 0xD1 and IRQ 21
ACPI: PCI Interrupt 0000:03:06.1[B] -> GSI 23 (level, low) -> IRQ 21
e1000: 0000:03:06.1: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:bf
e1000: eth5: e1000_probe: Intel(R) PRO/1000 Network Connection
ethtool -d eth3 shows 66Mhz:
....
0x00008: STATUS (Device status register) 0x00003B87
      Duplex:                            full
      Link up:                           link config
      TBI mode:                          disabled
      Link speed:                        1000Mb/s
      Bus type:                          PCI-X
      Bus speed:                         66MHz
      Bus width:                         64-bit

Quoted 1 line

Any idea why I see the slower bus speed reported?

ethtool currently doesn't know about some bus speeds, and will report a wrong speed. Here's what ethtool currently uses: (ethtool-3/e1000.c)

327 (reg & E1000_STATUS_PCIX_MODE) ?

328                         ((reg & E1000_STATUS_PCIX_SPEED_133) ? "133MHz" :
329                         (reg & E1000_STATUS_PCIX_SPEED_100) ? "100MHz" :
330                         "66MHz")>              :

obviously 120 is missing, but PCI-E speeds are also missing (2500gbps). The output of the e1000 module is correct.

Auke

Ben Greear

author

2006-05-12 22:26 UTC #2 lore raw

Quoted 2 lines · Auke Kok

obviously 120 is missing, but PCI-E speeds are also missing (2500gbps). The output of the e1000 module is correct.

Any idea why 120Mhz is used instead of 133? It doesn't seem to matter in my performance tests, but I am curious...

Thanks,
Ben

Signature · 2 lines

Ben Greear <[email protected]>
Candela Technologies Inc  http://www.candelatech.com

Chris Leech

2006-05-14 00:54 UTC #3 lore raw

Quoted 2 lines

Any idea why 120Mhz is used instead of 133? It doesn't seem to matter in my performance tests, but I am curious...

I think Rick is right, the bus between the bridge on the card and the e1000s is running at 120Mhz.

- Chris

Rick Jones

2006-05-12 21:41 UTC #4 lore raw

In reply to Ben Greear

Quoted 5 lines · Ben Greear

I'm running a slightly modified 2.6.16.13 kernel on FC5-amd64. The motherboard is SuperMicro H8SSL dual-core AMD system. According to super-micro web site, the PCI-X slot is 133Mhz. I'm using a 4-port pro/1000 NIC.
dmesg shows a listing of 120Mhz:

IIRC there is a bridge chip on those four-port cards. Perhaps the "north" side of the bridge is at 133 MHz, but the south side (since it is more than one load) is only 120?

Quoted 30 lines

Intel(R) PRO/1000 Network Driver - version 6.3.9-k4-NAPI Copyright (c) 1999-2005 Intel Corporation.
GSI 18 sharing vector 0xB9 and IRQ 18
ACPI: PCI Interrupt 0000:03:04.0[A] -> GSI 20 (level, low) -> IRQ 18
e1000: 0000:03:04.0: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:bc
e1000: eth2: e1000_probe: Intel(R) PRO/1000 Network Connection GSI 19 sharing vector 0xC1 and IRQ 19
ACPI: PCI Interrupt 0000:03:04.1[B] -> GSI 21 (level, low) -> IRQ 19
e1000: 0000:03:04.1: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:bd
e1000: eth3: e1000_probe: Intel(R) PRO/1000 Network Connection GSI 20 sharing vector 0xC9 and IRQ 20
ACPI: PCI Interrupt 0000:03:06.0[A] -> GSI 22 (level, low) -> IRQ 20
e1000: 0000:03:06.0: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:be
e1000: eth4: e1000_probe: Intel(R) PRO/1000 Network Connection GSI 21 sharing vector 0xD1 and IRQ 21
ACPI: PCI Interrupt 0000:03:06.1[B] -> GSI 23 (level, low) -> IRQ 21
e1000: 0000:03:06.1: e1000_probe: (PCI-X:120MHz:64-bit) 00:04:23:ad:41:bf
e1000: eth5: e1000_probe: Intel(R) PRO/1000 Network Connection
ethtool -d eth3 shows 66Mhz:
....
0x00008: STATUS (Device status register) 0x00003B87
      Duplex:                            full
      Link up:                           link config
      TBI mode:                          disabled
      Link speed:                        1000Mb/s
      Bus type:                          PCI-X
      Bus speed:                         66MHz
      Bus width:                         64-bit

Quoted 1 line

Any idea why I see the slower bus speed reported?

That one though escapes me.

rick jones

Quoted 6 lines

More info available as needed.
Thanks,
Ben