On Tue, 14 Jun 2011 13:04:29 -0600
Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
> This fixes a minor regression where broken PCI devices that use the
> reserved "11" memory BAR type worked before e354597cce but not after.
>
> The low four bits of a memory BAR are "PTT0" where P=1 for prefetchable
> BARs, and TT is as follows:
>
> 00 32-bit BAR, anywhere in lower 4GB
> 01 anywhere below 1MB (reserved as of PCI 2.2)
> 10 64-bit BAR
> 11 reserved
>
> Prior to e354597cce, we treated "0100" as a 64-bit BAR and all others,
> including prefetchable 64-bit BARs ("1100") as 32-bit BARs. The e354597cce
> fix, which appeared in 2.6.28, treats "x1x0" as 64-bit BARs, so the
> reserved "x110" types are treated as 64-bit instead of 32-bit.
>
> This patch returns to treating the reserved "11" type as a 32-bit BAR and
> adds a warning if we see it.
>
> It also logs a note if we see a 1M BAR. This is not a warning, because
> such hardware conforms to pre-PCI 2.2 spec, but I think it's worth noting
> because Linux ignores the 1M restriction if it ever has to assign the BAR.
>
> CC: Peter Chubb <peterc@xxxxxxxxxxxxxxxxxx>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=35952
> Reported-by: Jan Zwiegers <jan@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
Applied these guys, thanks Bjorn (and sorry for the delay! I should
have had you handling patches while I was traveling).
Thanks,
--
Jesse Barnes, Intel Open Source Technology Center
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