On Thu, Sep 14, 2023 at 10:33:03AM -0500, Bjorn Helgaas wrote:
> dev->no_d3cold appears to be mainly an administrative policy knob
> twidded via sysfs.
Actually the user space choice to disable D3cold is stored in a
different flag called pdev->d3cold_allowed.
The fact that d3cold_allowed_store() indirectly modifies the
no_d3cold flag as well looks like a bug that went unnoticed
for a couple of years. From a quick look, d3cold_allowed_store()
should probably call pci_bridge_d3_update() instead of
pci_d3cold_enable() / pci_d3cold_disable(). This was introduced by
commit 9d26d3a8f1b0 ("PCI: Put PCIe ports into D3 during suspend").
Perhaps Mika can chime in whether this is indeed wrong.
Thanks,
Lukas
