答复: [外部邮件] Re: [PATCH] PCI: Only restore state that was successfully saved around a reset

["Li,Rongqing" <lirongqing@baidu.com>]

> [Severity: High]
> Does skipping pci_restore_state() here introduce a regression that leaves the
> device unconfigured after a reset recovers it from an error?
> 
> Commit a2f1e22390ac ("PCI/ERR: Ensure error recoverability at all times") saves
> the initial config space in pci_bus_add_device() and removed the
> dev->state_saved check from pci_restore_state() so a valid baseline
> dev->state
> is always available even after a prior restore cleared dev->state_saved.
> 
> Commit e18d1abc3bff ("PCI: Avoid saving config space state if inaccessible")
> then skipped pci_save_state() in pci_dev_save_and_disable() when config space
> is inaccessible (such as during DPC) to avoid overwriting that preserved state
> with ~0 before the reset.
> 
> Since the hardware reset clears the device's registers back to power-on defaults,
> clearing dev->state_saved and skipping pci_restore_state() leaves BARs,
> PCI_COMMAND, capabilities, and bridge bus numbers unprogrammed once the
> reset makes config space accessible again.
> 
> [1] https://sashiko.dev/#/bug/linux-60bae679-5c85-4c49-8042-6817f9cb5c8f
> 

Sashiko is right — please drop this patch.

thanks

[Li,Rongqing] 

> --
> Sashiko AI
> review · https://sashiko.dev/#/patchset/20261110053348.2419-1-lirongqing
> @baidu.com?part=1