Re: [Intel-gfx] agp/intel: can't ioremap flush page - no chipset flushing

From: Bjorn Helgaas
Date: Fri Mar 07 2014 - 15:33:51 EST


On Thu, Mar 6, 2014 at 1:25 PM, Paul Bolle <pebolle@xxxxxxxxxx> wrote:
> Bjorn Helgaas schreef op ma 10-02-2014 om 14:33 [-0700]:
>> Can you open a kernel.org bugzilla report and attach complete dmesg
>> logs of the working and broken kernels to it? There might be more
>> useful resource-related messages from the PCI core.
>
> That took me quite a bit longer than I hoped, but I finally opened a
> report at
> https://bugzilla.kernel.org/show_bug.cgi?id=71611 .
>
> Note that the dmesg's are identical (up to that error). Are you still
> interested?

Thanks for attaching the dmesg log. I also attached the iomem
contents you previously posted.

This is likely a tangent from the AGP issue, but I don't understand
this iomem diff between v3.13.2 and v3.14-rc1:

-80000000-801fffff : PCI Bus 0000:02
-80200000-8027ffff : 0000:00:02.1

The first line is a bridge window to [bus 02], and the second is an
MMIO region for one of your AGP devices (00:02.0 is VGA and 00:02.1
seems to be some related device).

The bridge to [bus 02] is 00:1c.0, and your dmesg shows:

pci 0000:00:1c.0: PCI bridge to [bus 02]
pci 0000:00:1c.0: bridge window [io 0x6000-0x6fff]
pci 0000:00:1c.0: bridge window [mem 0xa0100000-0xa01fffff]

The [mem 0xa0100000-0xa01fffff] window appears in the dmesg log and in
both iomem captures; that makes good sense. The 80000000-801fffff
window is in only the v3.13.2 iomem, and it *should* appear in the
v3.13.2 dmesg log but apparently doesn't?

Likewise, the 00:02.1 resource appears only in the v3.13.2 iomem, and
it should also be mentioned in the v3.13.2 dmesg log. The v3.14-rc5
dmesg log shows an unassigned resource there:

pci 0000:00:02.1: reg 0x10: [mem 0x00000000-0x0007ffff]

and says we were unable to assign anything. But apparently v3.13.2
*did* assign something, and the dmesg log should show that.

Bjorn
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/