> -----Original Message----- > From: linux-kernel-owner@xxxxxxxxxxxxxxx [mailto:linux-kernel-owner@xxxxxxxxxxxxxxx] On Behalf Of > sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx > Sent: Monday, May 6, 2019 12:20 PM > To: bhelgaas@xxxxxxxxxx > Cc: linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; ashok.raj@xxxxxxxxx; > keith.busch@xxxxxxxxx; sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx > Subject: [PATCH v2 3/5] PCI/ATS: Skip VF ATS initialization if PF does not implement it > > From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> > > If PF does not implement ATS and VF implements/uses it, it might lead to > runtime issues. Also, as per spec r4.0, sec 9.3.7.8, PF should implement > ATS if VF implements it. So add additional check to confirm given device > aligns with the spec. ... > + /* > + * Per PCIe r4.0, sec 9.3.7.8, if VF implements Address Translation > + * Services (ATS) Extended Capability then corresponding PF should > + * also implement it. > + */ ... In standardese, "should" means recommended, not required. The PCIe spec uses "must" for this rule; the comments should match.
