Re: [PATCH v2 0/3] PCI: Revert / replace the cfg_access_lock lockdep mechanism

[Bjorn Helgaas <helgaas@kernel.org>]

On Thu, May 30, 2024 at 06:04:18PM -0700, Dan Williams wrote:
> Changes since v1 [1]:
> - split out the new warning into its own patch (Bjorn)
> - include the provisional fix to the pci_reset_bus() path
> 
> [1]: http://lore.kernel.org/r/171709637423.1568751.11773767969980847536.stgit@dwillia2-xfh.jf.intel.com
> 
> Hi Bjorn,
> 
> Here is the targeted revert of the cfg_access_lock lockdep
> infrastructure, but with the new proposed warning for catching "unlocked
> pci_bridge_secondary_bus_reset()" events broken out into its own change.
> I also included the proposed fix for at least one known case where
> pci_bridge_secondary_bus_reset() is being called without
> cfg_access_lock.
> 
> Given there may be more cases to unwind, and the fact that I am not
> convinced patch3 will be problem free I would, as you suggested,
> consider patch2 and patch3 v6.11 material. Patch1 is urgent for v6.10-rc
> to put out these lockdep false positive reports.
> 
> ---
> 
> Dan Williams (3):
>       PCI: Revert the cfg_access_lock lockdep mechanism
>       PCI: Warn on missing cfg_access_lock during secondary bus reset
>       PCI: Add missing bridge lock to pci_bus_lock()
> 
> 
>  drivers/pci/access.c    |    4 ----
>  drivers/pci/pci.c       |    8 +++++++-
>  drivers/pci/probe.c     |    3 ---
>  include/linux/lockdep.h |    5 -----
>  include/linux/pci.h     |    2 --
>  5 files changed, 7 insertions(+), 15 deletions(-)

Thanks, I applied the first to pci/for-linus for v6.10, and the others
to pci/reset for v6.11.

There will be a trivial conflict in -next and the v6.11 merge window
since pci/reset is based on v6.10-rc1 and contains some of the code
removed by the first patch.

Bjorn