ACK/Cmnt: [SRU] [RESEND] [J/K] [PATCH 00/10] Disable PTM when device is suspended for all PCIe devices

[Stefan Bader]

On 11.10.22 05:41, Kai-Heng Feng wrote:
> BugLink: https://bugs.launchpad.net/bugs/1988797
> 
> [Impact]
> Unsupporeted PTM requests can flood kernel dmesg. It can also prevent
> the system from suspending because the AER IRQ can never be quiesced.
> 
> [Fix]
> Disable PTM when PCIe device is suspended.
> 
> [Test]
> No more AER in dmesg, and affected system can suspend correctly.
> 
> [Where problems could occur]
> According to PCIe spec, disabling PTM is suggested, but it's possible
> that there are devices don't like PTM to be disabled during suspend.

What would be the visible effect if this happens? Errors on such devices or 
potentially they remain suspended? This is a somewhat substantial change and 
with it just reaching linux-next I would suspect there is not much experience 
with potential side effects. So it would be good to know what to watch out for.

Acked-by: Stefan Bader <stefan.bader at canonical.com>
> 
> Bjorn Helgaas (9):
>    PCI/PTM: Cache PTM Capability offset
>    PCI/PTM: Add pci_upstream_ptm() helper
>    PCI/PTM: Separate configuration and enable
>    PCI/PTM: Add pci_suspend_ptm() and pci_resume_ptm()
>    PCI/PTM: Move pci_ptm_info() body into its only caller
>    PCI/PTM: Preserve RsvdP bits in PTM Control register
>    PCI/PTM: Reorder functions in logical order
>    PCI/PTM: Consolidate PTM interface declarations
>    PCI/PM: Always disable PTM for all devices during suspend
> 
> Rajvi Jingar (1):
>    PCI/PM: Simplify pci_pm_suspend_noirq()
> 
>   drivers/pci/pci-driver.c |  30 ++--
>   drivers/pci/pci.c        |  28 +---
>   drivers/pci/pci.h        |  14 +-
>   drivers/pci/pcie/ptm.c   | 300 ++++++++++++++++++++++-----------------
>   include/linux/pci.h      |   3 +
>   5 files changed, 199 insertions(+), 176 deletions(-)
> 

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