Re: [PATCH v2 0/7] PCI: Solve two bridge window sizing issues

[Igor Mammedov]

On Thu, 28 Dec 2023 18:57:00 +0200
Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> wrote:

> Hi all,
> 
> Here's a series that contains two fixes to PCI bridge window sizing
> algorithm. Together, they should enable remove & rescan cycle to work
> for a PCI bus that has PCI devices with optional resources and/or
> disparity in BAR sizes.
> 
> For the second fix, I chose to expose find_empty_resource_slot() from
> kernel/resource.c because it should increase accuracy of the cannot-fit
> decision (currently that function is called find_resource()). In order
> to do that sensibly, a few improvements seemed in order to make its
> interface and name of the function sane before exposing it. Thus, the
> few extra patches on resource side.
> 
> Unfortunately I don't have a reason to suspect these would help with
> the issues related to the currently ongoing resource regression
> thread [1].

Jonathan,
can you test this series on affected machine with broken kernel to see if
it's of any help in your case?

> 
> [1] https://lore.kernel.org/linux-pci/ZXpaNCLiDM+Kv38H@xxxxxxxxxxxxxxxxxxx/
> 
> v2:
> - Add "typedef" to kerneldoc to get correct formatting
> - Use RESOURCE_SIZE_MAX instead of literal
> - Remove unnecessary checks for io{port/mem}_resource
> - Apply a few style tweaks from Andy
> 
> Ilpo Järvinen (7):
>   PCI: Fix resource double counting on remove & rescan
>   resource: Rename find_resource() to find_empty_resource_slot()
>   resource: Document find_empty_resource_slot() and resource_constraint
>   resource: Use typedef for alignf callback
>   resource: Handle simple alignment inside __find_empty_resource_slot()
>   resource: Export find_empty_resource_slot()
>   PCI: Relax bridge window tail sizing rules
> 
>  drivers/pci/bus.c       | 10 ++----
>  drivers/pci/setup-bus.c | 80 +++++++++++++++++++++++++++++++++++++----
>  include/linux/ioport.h  | 44 ++++++++++++++++++++---
>  include/linux/pci.h     |  5 +--
>  kernel/resource.c       | 68 ++++++++++++++++-------------------
>  5 files changed, 148 insertions(+), 59 deletions(-)
>