Re: [PATCH net-next 0/4] RDMA/net/ionic: Misc updates

["Creeley, Brett" <bcreeley@amd.com>]

On 5/14/2026 9:40 AM, Leon Romanovsky wrote:
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>
> On Thu, May 14, 2026 at 08:03:09PM +0530, Abhijit Gangurde wrote:
>> On 5/7/26 04:29, Jakub Kicinski wrote:
>>> On Tue, 5 May 2026 21:19:31 -0700 Eric Joyner wrote:
>>>> Other smaller additions add a devlink parameter to the ionic ethernet
>>>> driver for enabling and disabling RDMA,
>>> My understanding is that the devlink param was expected to change
>>> the configuration of the device. IOW user can enable/disable RDMA
>>> to save internal device resources. You seem to be purely preventing
>>> the auxbus device to be added. So there's nothing gained here compared
>>> to simply not loading the RDMA driver. What am I missing?
>> You're right that the current implementation controls only the auxiliary bus
>> device registration and doesn't reconfigure firmware resource allocation.
>> The intent behind this devlink param is to provide per-device granularity
>> for enabling/disabling RDMA. In a system with multiple ionic NICs, an
>> administrator may want RDMA active on some devices but not others.
>> That said, if this per-device control justification is sufficient on its
>> own, or if firmware-side changes are a hard requirement for this to be
>> acceptable?
> I'm confident that the administrator can vibe code an appropriate udev
> rule and disable autoprobing for this case.
>
> The real advantage of a devlink knob here is the ability to control the
> firmware.
>
> Thanks

Based on the documentation in devlink-params.rst, the devlink knob for 
enable_rdma indicates that when enabled the driver will instantiate RDMA 
specific auxiliary device of the devlink device. The documentation 
doesn't state what to do when enable_rdma is disabled, but it seemed 
like removing the auxiliary device provided the opposite behavior of 
enabled.

If that's not the case, does the documentation need to be updated 
accordingly?

Thanks,

Brett


>
>> Thanks,
>> Abhijit