Re: [PATCH v2 1/3] usb: hcd-pci: Honour pci_save_state() failure

[sashiko-bot@kernel.org]

> hcd_pci_suspend_noirq() ignores the return value of pci_save_state() and
> goes on to pci_prepare_to_sleep().
> 
> The next patch makes pci_save_state() fail, without marking the state as
> saved, when the config space of the device is not accessible.  For such
> a controller pci_prepare_to_sleep() does not work either:
> pci_set_low_power_state() reads the PM control register as all ones and
> marks the device D3cold.  pci_pm_suspend_noirq() then finds a device
> whose power state changed without its state being saved, and warns.
> With an earlier version of the next patch on a MacBookPro14,3, whose
> Thunderbolt xHCI controllers can be inaccessible at this point:
> 
>   xhci_hcd 0000:7d:00.0: PCI PM: State of device not saved by hcd_pci_suspend_noirq+0x0/0x180
>   WARNING: CPU: 7 PID: 96793 at drivers/pci/pci-driver.c:888 pci_pm_suspend_noirq+0x2f4/0x300
> 
> [ ... ]
> in D0 instead of being put into a low-power state with an incomplete
> saved state.
> 
> Assisted-by: LLM
> Signed-off-by: Francisco Beltrán Millalén <fbeltranmillalen@gmail.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260930141914.6678-1-fbeltranmillalen@gmail.com?part=1