Re: [PATCH v12 0/8] PCI: Expose and manage PCI device reset

From: Bjorn Helgaas
Date: Wed Jul 28 2021 - 13:24:12 EST


On Fri, Jul 16, 2021 at 10:19:38AM -0500, Shanker Donthineni wrote:
> PCI and PCIe devices may support a number of possible reset mechanisms
> for example Function Level Reset (FLR) provided via Advanced Feature or
> PCIe capabilities, Power Management reset, bus reset, or device specific reset.
> Currently the PCI subsystem creates a policy prioritizing these reset methods
> which provides neither visibility nor control to userspace.
>
> Expose the reset methods available per device to userspace, via sysfs
> and allow an administrative user or device owner to have ability to
> manage per device reset method priorities or exclusions.
> This feature aims to allow greater control of a device for use cases
> as device assignment, where specific device or platform issues may
> interact poorly with a given reset method, and for which device specific
> quirks have not been developed.
>
> Changes in v12:
> - Corrected subject in 0/8 (cover letter).
>
> Changes in v11:
> - Alex's suggestion fallback back to other resets if the ACPI RST
> fails. Fix "s/-EINVAL/-ENOTTY/" in 7/8 patch.

Sorry I missed the fact that you posted the v12 of this series when I
looked at the v10 from Amey yesterday. But the only code change from
v10 to v12 is the pci_dev_acpi_reset() return value change, so my
comments should all apply to this v12.