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

Or Gerlitz
2015-05-20T14:40:57Z

On 5/20/2015 3:29 AM, Jason Gunthorpe wrote:
> On Tue, May 19, 2015 at 10:30:00PM +0300, Or Gerlitz wrote:
>> >Are you objecting adding the clock frequency and mask to the qeury device verb?
>> >why?
> Lets see the verbs side and I'll let you know.

You mean the user series of libibverbs/libmlx4? I don't see why this
should be a must for the review of the kernel bits. The user-space code
is coming up soon, sure, but we should be able to review kernel patches
without requiring to actually see the user-space code.

As the change-logs here explained, the clock frequency is needed for
applications to convert the HCA clock delta (current time - timestamp on
WC) into nano-secs and such.The mask is needed to realize how many bits
from the 64b time-stamp are supported by the HW.

>
>> >If not, are objecting using the vendor specific track of the verb to
>> >pass from the vendor driver to the vendor library this or that detail
>> >which is needed for proper operation? why?
> I'm uncomfortable seeing otherwise vendor-neutral calls gain vendor
> extensions.

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.

Or.