Re: [PATCH for-next 09/10] IB/mlx4: Add timestamp_mask and hca_core_clock to query_device

Or Gerlitz
2015-05-20T17:53:02Z

On Wed, May 20, 2015 at 6:11 PM, Yann Droneaud <ydroneaud-RlY5vtjFyJ3QT0dZR+AlfA@public.gmane.org> wrote:

>> But this is whole purpose of the udata framework in uverbs, right? for
>> each uverb command the vendor user-space library has a well defined
>> channel to communicate directly with the low level vendor driver
>> throughout the uverbs channels.

> Uverbs convey information between kernel and userspace drivers to
> implement verbs for userspace application. I don't think it's designed
> to allow vendor to add random extensions in the best way with regard to
> backward/forward compability.

Disagree that this is random extension. The people that designed this
stack 10y ago (Roland and Co.) looked very nicely forward and realized
that not all the HW are the same nor can be put 101% under the same
API with no way out, and hence they came up with udata.

Please state how you see the role of the uverbs udata mechanism.