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

Or Gerlitz
2015-05-23T04:26:47Z

On Wed, May 20, 2015 at 8:53 PM, Or Gerlitz <gerlitz.or-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> 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.

Guys, still waiting to hear why you think it's wrong here to use the
mechanism which was built from day-1 for the purpose of allowing the
user-space driver library to communicate with the kernel driver and
pass values in both directions.

Or.