Re: [PATCH v5 02/18] PCI/CXL: Probe the underlying bus reset in cxl_reset_bus_function()

[Nicolin Chen <nicolinc@nvidia.com>]

On Thu, Aug 27, 2026 at 05:31:31PM -0300, Jason Gunthorpe wrote:
> > [ ... 27 lines skipped ... ]
> > @@ -4979,8 +4979,16 @@ static int cxl_reset_bus_function(struct pci_dev *dev, bool probe)
> >  	if (!dvsec)
> >  		return -ENOTTY;
> >  
> > -	if (probe)
> > -		return 0;
> > +	/*
> > +	 * Do not probe via pci_reset_bus_function(), which would reject a
> > +	 * masked SBR that the do-reset path below unmasks before resetting.
> > +	 */
> > +	if (probe) {
> > +		rc = pci_dev_reset_slot_function(dev, PCI_RESET_PROBE);
> > +		if (rc != -ENOTTY)
> > +			return rc;
> > +		return pci_parent_bus_reset(dev, PCI_RESET_PROBE);
> > +	}
> 
> Why not put this a little lower after the:
> 
> >
> >  	rc = pci_read_config_word(bridge, dvsec + PCI_DVSEC_CXL_PORT_CTL, &reg);
> >  	if (rc)
> 
> ?

Hmm, the "if (probe)" was checked before pci_read_config_word, so I
kept it there. I don't quite get the reason of putting it behind.

Mind elaborating?

Thanks
Nicolin