[U-Boot] [PATCH v2] pci: Avoid assigning PCI resources that are below 0x1000

Bin Meng bmeng.cn at gmail.com
Wed Jun 19 07:12:33 UTC 2019

Hi Stefan,

On Wed, Jun 5, 2019 at 10:26 PM Bin Meng <bmeng.cn at gmail.com> wrote:
> commit b7598a43f2b4 ("[PATCH] Avoid assigning PCI resources from
> zero address") only moved the bus lower address to 0x1000 if the
> given bus start address is zero. The comment said 0x1000 is a
> reasonable starting value, hence we'd better apply the same
> adjustment when the given bus start address is below 0x1000.
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> ---
> Changes in v2:
> - avoid changing res->bus_start

Somehow I did not receive your RB in my inbox. However when I look at
the patch in patchwork [1], I found you already gave your RB tag, so
there must have be something wrong with gmail.

Regarding your question, first it was just pure code review before and
at that time I did not spot any actual issue. However I indeed created
a test case to trigger the issue.

If I modified qemu-x86_i440fx.dts pci range to have the PCI IO region
address starts from 0x100, when Linux boots, it reports the following:
[    0.445751] pci 0000:00:03.0: can't claim BAR 1 [io
0x0140-0x017f]: address conflict with 0000:00:01.1 [io  0x0170-0x0177]

With my patch, there is no longer such complaints from the kernel driver.

[1] http://patchwork.ozlabs.org/patch/1110510/


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