Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 23 Jun 2023 08:12:53 -0500 | Subject | Re: [PATCH v3 2/2] PCI: pciehp: Clear the optional capabilities in DEVCTL2 on a hot-plug | From | Jay Cornwall <> |
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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.
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