tree 87ae9c052e275dbeed6fe8e9e10ccdc6f8a0ccbc
parent 2bdd1b031b200d55c2512c8d7e0e9bdcf85d011f
author Bertram Felgenhauer <int-e@gmx.de> 1212705082 -0700
committer Jesse Barnes <jbarnes@virtuousgeek.org> 1212705135 -0700

x86/PCI: add workaround for bug in ASUS A7V600 BIOS (rev 1005)

This BIOS claims the VIA 8237 south bridge to be compatible with VIA 586,
which it is not.

Without this patch, I get the following warning while booting,
among others,

| PCI: Using IRQ router VIA [1106/3227] at 0000:00:11.0
| ------------[ cut here ]------------
| WARNING: at arch/x86/pci/irq.c:265 pirq_via586_get+0x4a/0x60()
| Modules linked in:
| Pid: 1, comm: swapper Not tainted 2.6.26-rc4-00015-g1ec7d99 #1
|  [<c0119fd4>] warn_on_slowpath+0x54/0x70
|  [<c02246e0>] ? vt_console_print+0x210/0x2b0
|  [<c02244d0>] ? vt_console_print+0x0/0x2b0
|  [<c011a413>] ? __call_console_drivers+0x43/0x60
|  [<c011a482>] ? _call_console_drivers+0x52/0x80
|  [<c011aa89>] ? release_console_sem+0x1c9/0x200
|  [<c0291d21>] ? raw_pci_read+0x41/0x70
|  [<c0291e8f>] ? pci_read+0x2f/0x40
|  [<c029151a>] pirq_via586_get+0x4a/0x60
|  [<c02914d0>] ? pirq_via586_get+0x0/0x60
|  [<c029178d>] pcibios_lookup_irq+0x15d/0x430
|  [<c03b895a>] pcibios_irq_init+0x17a/0x3e0
|  [<c03a66f0>] ? kernel_init+0x0/0x250
|  [<c03a6763>] kernel_init+0x73/0x250
|  [<c03b87e0>] ? pcibios_irq_init+0x0/0x3e0
|  [<c0114d00>] ? schedule_tail+0x10/0x40
|  [<c0102dee>] ? ret_from_fork+0x6/0x1c
|  [<c03a66f0>] ? kernel_init+0x0/0x250
|  [<c03a66f0>] ? kernel_init+0x0/0x250
|  [<c010324b>] kernel_thread_helper+0x7/0x1c
|  =======================
| ---[ end trace 4eaa2a86a8e2da22 ]---

and IRQ trouble later,

| irq 10: nobody cared (try booting with the "irqpoll" option)

Now that's an VIA 8237 chip, so pirq_via586_get shouldn't be called
at all; adding this workaround to via_router_probe() fixes the
problem for me.

Amazingly I have a 2.6.23.8 kernel that somehow works fine ... I'll
never understand why.

Signed-off-by: Bertram Felgenhauer <int-e@gmx.de>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>