Re: [PATCH rdma-core] mlx5: Return pointer to CQ doorbell

Leon Romanovsky
2017-08-23T16:45:55Z

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On Wed, Aug 23, 2017 at 10:08:16AM -0600, Jason Gunthorpe wrote:
> On Wed, Aug 23, 2017 at 03:13:38PM +0300, Yishai Hadas wrote:
> > On 8/22/2017 7:30 PM, Jason Gunthorpe wrote:
> > >On Tue, Aug 22, 2017 at 11:36:42AM +0300, Yishai Hadas wrote:
> > >>On 8/21/2017 6:22 PM, Jason Gunthorpe wrote:
> > >>>Is there existing code out there that uses cq_out->uar and works
> > >>>properly today? Yes or No?
> > >>
> > >>No, only this fix enables that to work properly.
> >
> > >Particularly since a patch to do this with proper compatibility
> > >exists, and there is no reason at all to take a shortcut.
> > >
> >
> > We are not looking for a shortcut but for a solution that will match
> > majority users if not all.
>
> Here is the patch that takes care of everything properly. It is PR
> 188.
>
> Please be more careful with the ABI requirements in the future.
>
> From 32ef444e45006112ff759106dcdee2b99999501a Mon Sep 17 00:00:00 2001
> From: Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
> Date: Wed, 23 Aug 2017 10:05:24 -0600
> Subject: [PATCH] mlx5: Fix ABI break from revising the UAR pointer
>
> Provide two implementations of mlx5dv_init_obj, one that has the
> historical behaviour that has existed until now of returning the
> void **uar and a new version that returns the 'void *' version
> renamed to arb_db.

arb_db -> arm_db

>
> Apps that use this feature must refer to it as arb_db, they will not
> compile on pre-rdma-core 15 releases, and they will not dynamically
> link to old versions either. This provides a sane level of safety for
> the end users of this library.
>
> Fixes: c6e3439aaa93 ("mlx5: Return pointer to CQ doorbell")

Strange, in github it has 7 digits (the same was with rsocket fixes)
Fixes: c6e3439 ("mlx5: Return pointer to CQ doorbell")

> Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> Signed-off-by: Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>

The overall looks good, but I need to run checks with before applying it.

Thanks for doing it.

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