pci-to-pci bridges on ip32

pci-to-pci bridges on ip32

[Giuseppe Sacco]

Hi all,
I have a PCI board that is not recognised by Linux on MIPS. Its ID is
9710:9250, using an MCS9250 PCI-to-PCI chip manufactured by MosCHIP
(a.k.a. Netmos). 

I checked the board on i386 and it works correctly. All devices on that
board are recognised and every driver is loaded by udev upon startup.

Is there any problem with pci-to-pci bridges on mips ip32?

Thanks,
Giuseppe

Re: pci-to-pci bridges on ip32

[Ralf Baechle]

On Tue, Sep 11, 2007 at 08:55:46PM +0200, Giuseppe Sacco wrote:

> Hi all,
> I have a PCI board that is not recognised by Linux on MIPS. Its ID is
> 9710:9250, using an MCS9250 PCI-to-PCI chip manufactured by MosCHIP
> (a.k.a. Netmos). 
> 
> I checked the board on i386 and it works correctly. All devices on that
> board are recognised and every driver is loaded by udev upon startup.
> 
> Is there any problem with pci-to-pci bridges on mips ip32?

Can you give a few more details on the sympthom with this card on IP32?

  Ralf

Re: pci-to-pci bridges on ip32

[Giuseppe Sacco]

Hi Ralf,

Il giorno gio, 13/09/2007 alle 00.20 +0100, Ralf Baechle ha scritto:
[...]
> Can you give a few more details on the sympthom with this card on IP32?
> 
>   Ralf

I have an SGI O2 with an R5000 CPU, 1 SCSI CD-ROM, 2 SCSI disks, 128Mb
of RAM and a PCI ethernet card. I replaced the PCI card with this new
board, but it seems the board is listed but otherwise ignored. The only
trace is in lspci output. There isn't a list of devices in the other
side of this PCI-to-PCI chip.

# lspci
00:01.0 SCSI storage controller: Adaptec AIC-7880U
00:02.0 SCSI storage controller: Adaptec AIC-7880U
00:03.0 PCI Bridge: Netmos technology Unknown device 9250
(The card vendor and product are IDs 9710:9250.)

When I plug the card on an i386 machine, it is recognised since lspci
display the card and all three devices present on the same card (devices
accessible via the PCI-to-PCI bridge). All these devices are available
to udev, so udev start all relevant drivers.

I started checking my kernel config. Do I have to activate any specific
CONFIG_?? option in order to use such a card (beside the driver for all
devices).

Actually I have:

CONFIG_HW_HAS_PCI=y
CONFIG_PCI=y
CONFIG_MMU=y
# CONFIG_HOTPLUG_PCI is not set

while on i386 I have:

CONFIG_PCI=y
# CONFIG_PCI_GOBIOS is not set
# CONFIG_PCI_GOMMCONFIG is not set
# CONFIG_PCI_GODIRECT is not set
CONFIG_PCI_GOANY=y
CONFIG_PCI_BIOS=y
CONFIG_PCI_DIRECT=y
CONFIG_PCI_MMCONFIG=y
CONFIG_PCIEPORTBUS=y
CONFIG_HOTPLUG_PCI_PCIE=m
# CONFIG_HOTPLUG_PCI_PCIE_POLL_EVENT_MODE is not set
CONFIG_PCI_MSI=y
CONFIG_HOTPLUG_PCI=m
CONFIG_HOTPLUG_PCI_FAKE=m
CONFIG_HOTPLUG_PCI_COMPAQ=m
# CONFIG_HOTPLUG_PCI_COMPAQ_NVRAM is not set
CONFIG_HOTPLUG_PCI_IBM=m
CONFIG_HOTPLUG_PCI_ACPI=m
CONFIG_HOTPLUG_PCI_ACPI_IBM=m
CONFIG_HOTPLUG_PCI_CPCI=y
CONFIG_HOTPLUG_PCI_CPCI_ZT5550=m
CONFIG_HOTPLUG_PCI_CPCI_GENERIC=m
CONFIG_HOTPLUG_PCI_SHPC=m

I am using kernel 2.6.18 on both machines, as shipped with Debian
stable.

Thanks,
Giuseppe

Re: pci-to-pci bridges on ip32

[Ralf Baechle]

On Thu, Sep 13, 2007 at 02:48:19PM +0200, Giuseppe Sacco wrote:

> Il giorno gio, 13/09/2007 alle 00.20 +0100, Ralf Baechle ha scritto:
> [...]
> > Can you give a few more details on the sympthom with this card on IP32?
> > 
> >   Ralf
> 
> I have an SGI O2 with an R5000 CPU, 1 SCSI CD-ROM, 2 SCSI disks, 128Mb
> of RAM and a PCI ethernet card. I replaced the PCI card with this new
> board, but it seems the board is listed but otherwise ignored. The only
> trace is in lspci output. There isn't a list of devices in the other
> side of this PCI-to-PCI chip.
> 
> # lspci
> 00:01.0 SCSI storage controller: Adaptec AIC-7880U
> 00:02.0 SCSI storage controller: Adaptec AIC-7880U
> 00:03.0 PCI Bridge: Netmos technology Unknown device 9250
> (The card vendor and product are IDs 9710:9250.)
> 
> When I plug the card on an i386 machine, it is recognised since lspci
> display the card and all three devices present on the same card (devices
> accessible via the PCI-to-PCI bridge). All these devices are available
> to udev, so udev start all relevant drivers.
> 
> I started checking my kernel config. Do I have to activate any specific
> CONFIG_?? option in order to use such a card (beside the driver for all
> devices).

I got a quad Tulip card on my Malta here and that works fine:

# lspci
00:0a.0 ISA bridge: Intel Corp. 82371AB/EB/MB PIIX4 ISA (rev 02)
00:0a.1 IDE interface: Intel Corp. 82371AB/EB/MB PIIX4 IDE (rev 01)
00:0a.2 USB Controller: Intel Corp. 82371AB/EB/MB PIIX4 USB (rev 01)
00:0a.3 Bridge: Intel Corp. 82371AB/EB/MB PIIX4 ACPI (rev 02)
00:0b.0 Ethernet controller: Advanced Micro Devices [AMD] 79c970 [PCnet LANCE] (rev 43)
00:0c.0 Multimedia audio controller: Cirrus Logic Crystal CS4281 PCI Audio (rev 01)
00:11.0 Host bridge: Unknown device df53:0001 (rev 97)
00:12.0 PCI bridge: Digital Equipment Corporation DECchip 21154 (rev 05)
00:13.0 Ethernet controller: Digital Equipment Corporation DECchip 21040 [Tulip] (rev 23)
01:04.0 Ethernet controller: Digital Equipment Corporation DECchip 21142/43 (rev 41)
01:05.0 Ethernet controller: Digital Equipment Corporation DECchip 21142/43 (rev 41)
01:06.0 Ethernet controller: Digital Equipment Corporation DECchip 21142/43 (rev 41)
01:07.0 Ethernet controller: Digital Equipment Corporation DECchip 21142/43 (rev 41)
#


> I am using kernel 2.6.18 on both machines, as shipped with Debian
> stable.

I wonder if somebody hacked that kernel to just scan the PCI bus.  That
means it would trust whatever the ARCS firmware has setup and ARCS is
definately broken, doesn't know how to handle PCI-to-PCI bridges and will
just skip over them.  Exactly what you observe.

  Ralf