Re: [PATCH 2/3] PCI: Create new reset method to force SBR for CXL

Lukas Wunner
2024-03-12T07:50:12Z

On Mon, Mar 11, 2024 at 01:39:54PM -0700, Dave Jiang wrote:
> CXL spec r3.1 8.1.5.2
> By default Secondary Bus Reset (SBR) is masked for CXL ports. Introduce a
> new PCI reset method "cxl_bus_force" to force SBR on CXL ports by setting
> the unmask SBR bit in the CXL DVSEC port control register before performing
> the bus reset and restore the original value of the bit post reset.

Hm, why not have a sysfs attribute (or sysctl variable) to unmask SBR?

That would avoid the need to touch pci code as the sysfs attribute could
be kept local to the cxl subsystem.

Thanks,

Lukas