On 6/22/2023 16:42, Lukas Wunner wrote: > I don't now why commit 430a23689dea, which introduced > pci_enable_atomic_ops_to_root(), chose to add it as a library function > which is only called from specific drivers, instead of universally > enabling the feature for all devices. Adding the commit authors to cc > so they can chime in. IIRC during the initial design discussion on linux-pci this approach was suggested to avoid triggering potential bugs in devices without AtomicOps support. See quote below. I've no objections to changing it. On 2016-05-06 10:48, Bjorn Helgaas wrote: > Once enabled in Device Control 2, a device's use of AtomicOps is > competely device-specific. In many cases, the device probably doesn't > support AtomicOps, so enabling them would be a no-op. But there could > be devices where AtomicOps are nominally supported but untested or > broken. Even if we didn't change their drivers, those devices could > start using AtomicOps, so I'm not comfortable with the PCI core > enabling AtomicOp requests indiscriminately.
