Re: [PATCH for-next] RDMA/qedr: Remove unsupported qedr_resize_cq callback

[Kamal Heib <kamalheib1@gmail.com>]

On Mon, Oct 25, 2021 at 09:24:41AM +0000, Prabhakar Kushwaha wrote:
> Dear Kamal,
> 

Hi Prabhakar,

> > -----Original Message-----
> > From: Kamal Heib <kamalheib1@gmail.com>
> > Sent: Monday, October 25, 2021 9:27 AM
> > To: linux-rdma@vger.kernel.org
> > Cc: Michal Kalderon <mkalderon@marvell.com>; Ariel Elior
> > <aelior@marvell.com>; Doug Ledford <dledford@redhat.com>; Jason
> > Gunthorpe <jgg@ziepe.ca>; Kamal Heib <kamalheib1@gmail.com>
> > Subject:  [PATCH for-next] RDMA/qedr: Remove unsupported
> > qedr_resize_cq callback
> > 
> > External Email
> > 
> > ----------------------------------------------------------------------
> > There is no need to return always zero for function which is not supported.
> > 
> > Fixes: a7efd7773e31 ("qedr: Add support for PD,PKEY and CQ verbs")
> > Signed-off-by: Kamal Heib <kamalheib1@gmail.com>
> > ---
> >  drivers/infiniband/hw/qedr/main.c  |  1 -  drivers/infiniband/hw/qedr/verbs.c |
> > 10 ----------  drivers/infiniband/hw/qedr/verbs.h |  1 -
> >  3 files changed, 12 deletions(-)
> 
> Have you tested this patch? I afraid, there may be a crash because of  this 
>

I do not think that we will face a crash, because the libqedr in the
rdma-core package dose not implement the resize_cq() callback.

Furthermore, if there is a bug in the kernel rdma core this doesn't mean
that the qedr driver need to fake supporting resize_cq() to avoid a crash!.

Anyway, To be in the safe side we I'll prepare another patch that checks
for NULL in the core and return -EOPNOTSUPP if resize_cq() is not set
by the driver.


> static int ib_uverbs_resize_cq(struct uverbs_attr_bundle *attrs)
> {
> <snip>
> 
>         cq = uobj_get_obj_read(cq, UVERBS_OBJECT_CQ, cmd.cq_handle, attrs);
>         if (!cq)
>                 return -EINVAL;
> 
>         ret = cq->device->ops.resize_cq(cq, cmd.cqe, &attrs->driver_udata);    <<<< No check for NULL.
> 
> 
> --pk
>

Thanks,
Kamal