Re: [PATCH v3] s390/pci: Avoid deadlock between PCI error recovery and mlx5 crdump

[Heiko Carstens <hca@linux.ibm.com>]

On Thu, Oct 16, 2025 at 11:27:03AM +0200, Gerd Bayer wrote:
> Do not block PCI config accesses through pci_cfg_access_lock() when
> executing the s390 variant of PCI error recovery: Acquire just
> device_lock() instead of pci_dev_lock() as powerpc's EEH and
> generig PCI AER processing do.
> 
> During error recovery testing a pair of tasks was reported to be hung:
> 
> mlx5_core 0000:00:00.1: mlx5_health_try_recover:338:(pid 5553): health recovery flow aborted, PCI reads still not working
> INFO: task kmcheck:72 blocked for more than 122 seconds.
>       Not tainted 5.14.0-570.12.1.bringup7.el9.s390x #1
> Cc: stable@vger.kernel.org
> Fixes: 4cdf2f4e24ff ("s390/pci: implement minimal PCI error recovery")
> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
> Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
> ---
> Hi Niklas, Shay, Jason,
> 
> by now I believe fixing this in s390/pci is the right way to go, since
> the other PCI error recovery implementations apparently don't require
> this strict blocking of accesses to the PCI config space.
>     
> Hi Alexander, Vasily, Heiko,
>     
> while I sent this to netdev since prior versions were discussed there,
> I assume this patch will go through the s390 tree, right?

Applied, thanks!