Subject: Re: CVS commit: syssrc
To: None <jhawk@MIT.EDU>
From: Noriyuki Soda <email@example.com>
Date: 07/19/2000 03:31:02
> | syssrc/sys/arch/i386/pci: pci_intr_fixup.c
> | cvs rdiff -r1.6 -r1.7 syssrc/sys/arch/i386/pci/pci_intr_fixup.c
> This stuff is pretty confusing already. Could some of the documentation
> that you've placed in the log messages make it somewhere that's useful
> to users trying to configure this, such as pcibios(4)?
I hope that GENERIC configuration has the following options.
(i.e. almost all PCIBIOS options enabled.)
# Configure PCI using BIOS information
options PCIBIOS # PCI BIOS support
options PCIBIOSVERBOSE # PCI BIOS verbose info
options PCIBIOS_BUS_FIXUP # fixup PCI bus numbering
options PCIBIOS_ADDR_FIXUP # fixup PCI I/O addresses
options PCIBIOS_INTR_FIXUP # fixup PCI interrupt routing
options PCIBIOS_IRQS_HINT=0 # PCI interrupts hint.
#options PCIINTR_DEBUG # super-verbose PCI interrupt fixup
I suppose that PCIBIOS_BUS_FIXUP is already stable, and probably
it is OK to enable this option by default.
Uchiyama-san said PCIBIOS_ADDR_FIXUP may still have problem with
pccbb (cardbus bridge), so probably it is a bit early to to enable
this for now.
About PCIBIOS_INTR_FIXUP, I believe that pci_intr_fixup.c revision 1.7
is more robust than previous version. So, please try to enable
this option with the revision 1.7. I hope this option enabled
Anyway, the description of pcibios.4 should be improved.
For example, I think pcibios.4 should have the following descriptions.
(Please correct if there is incorrect or misleading description,
also please correct mistakes about English expression.)
Some BIOS doesn't allocate I/O space and memory space for
some PCI devices. Especially, BIOS which is PnP OS mode
enabled shows this behavior. Also many BIOS leaves CardBus
bridge's space unallocated. Since necessary space isn't
allocated, those devices will not work in this situation.
This option allocates the I/O space and memory space
instead of such BIOS.
If the space is already correctly assigned to devices,
this option leaves I/O space and memory space as is,
Each PCI bus and CardBus should have unique bus number.
But some BIOS doesn't assign bus number for subordinate
PCI buses. And many BIOS doesn't assign bus number for
Typical symptom of this is the following boot message:
cardbus0 at cardslot0: bus 0 device 0...
Please note that this cardbus0 has a bus number `0',
but normally the bus number 0 is used by the machine's
primary PCI bus, thus, this bus number for cardbus is
incorrect (not assigned). In this situation, a device
located in cardbus0 doesn't show correct device ID,
because it's bus number 0 incorrectly refers primary
PCI bus, a device ID in the primary PCI bus are shown
in boot message instead of the device's ID in the cardbus0.
This option assigns bus numbers for all subordinate
PCI buses and CardBuses.
Since this option renumbers all PCI buses and CardBuses,
all bus numbers of subordinate buses becomes different
when this option enabled.
Some BIOS doesn't assign interrupt for some devices.
This option assigns interrupt for such devices instead
of such BIOS.
This option leaves already assigned interrupt as is.
PCIBIOS_INTR_FIXUP tries to detect a IRQ which can be used
for a PCI device. This option specifies a hint which is
used when the automatic IRQ detection doesn't work.
Ths value is a logical-or of power-of-2s of allowable interrupts:
IRQ Val IRQ Val IRQ Val IRQ Val
0 0x0001 4 0x0010 8 0x0100 12 0x1000
1 0x0002 5 0x0020 9 0x0200 13 0x2000
2 0x0004 6 0x0040 10 0x0400 14 0x4000
3 0x0008 7 0x0080 11 0x0800 15 0x8000
For example, "options PCIBIOS_IRQS_HINT=0x0a00" allows
irq 9 and irq 11.
Kernel global variable `pcibios_irqs_hint' holds this value,
so a user can override this value without kernel recompilation.
- To specify this value on the fly, type "boot -d" on
boot prompt to drop into DDB (the in-kernel debuger,
you have to specify "options DDB" to make kernel with DDB).
Specify "write pcibios_irqs_hint 0x0a00" on "db>" prompt
and type "c" to continue to boot.
- To modify kernel image without kernel recompilation,
run "gdb --write /netbsd" on shell,
type "set pcibios_irqs_hint=0xa00" on "(gdb)" prompt,
and type "quit"
Some buggy BIOS provides inconsistent information between
PCI Interrupt Configuration Register and PCI Interrupt
Routing table. In such case, PCI Interrupt Configuration
Register takes precedence by default. If this happens,
a kernel with PCIBIOSVERBOSE shows "WARNING: leave irq XX"
in the PCI routing table.
If PCIBIOS_INTR_FIXUP_FORCE is specified in addtion to
PCIBIOS_INTR_FIXUP, PCI Interrupt Routing table takes
precedence. In this case, a kernel with PCIBIOSVERBOSE
shows "WARNING: override irq XX" in the PCI routing table.
Display detailed information about PCIBIOS_INTR_FIXUP processing.
If one of the above PCIBIOS_* options is used, this option
should be specified, too.
Display information about PCIBIOS processing.