Re: [PATCH for-next] RDMA/efa: Validate SQ depth based on WQE size

[Leon Romanovsky <leon@kernel.org>]

On Thu, May 14, 2026 at 08:45:21PM +0000, Yonatan Nachum wrote:
> On Thu, May 14, 2026 at 07:28:12PM +0300, Leon Romanovsky wrote:
> > On Wed, May 13, 2026 at 07:24:51PM +0000, Yonatan Nachum wrote:
> > > On Wed, May 13, 2026 at 08:38:12PM +0300, Leon Romanovsky wrote:
> > > > On Thu, May 07, 2026 at 11:21:10AM +0000, Yonatan Nachum wrote:
> > > > > From: Michael Margolin <mrgolin@amazon.com>
> > > > > 
> > > > > Change the SQ depth validation to take into account the SQ WQE size.
> > > > > This is needed since when using 128-byte WQE the max SQ depth is cut in
> > > > > half. On create QP command, userspace provides SQ ring size which is SQ
> > > > > depth X WQE size so we can calculate the requested WQE size in the
> > > > > kernel.
> > > > > 
> > > > > Reviewed-by: Daniel Kranzdorf <dkkranzd@amazon.com>
> > > > > Reviewed-by: Michael Margolin <mrgolin@amazon.com>
> > > > > Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
> > > > > ---
> > > > >  drivers/infiniband/hw/efa/efa_verbs.c | 39 ++++++++++++++++++---------
> > > > >  1 file changed, 27 insertions(+), 12 deletions(-)
> > > > 
> > > > Please add Fixes line.
> > > > 
> > > > Thanks
> > > 
> > > There is no Fixes tag as this is not a bug fix. The existing validation
> > > works but is overly permissive — it doesn't account for WQE size when
> > > checking max SQ depth. Without it, the device would reject the request
> > > downstream. This patch tightens the validation to fail early in the
> > > kernel.
> > 
> > So why do we need kernel patch after all?
> > 
> > Thanks
> 
> The driver already validates max_send_wr against max_sq_depth — this
> patch just makes that check accurate for the 128-byte WQE case. This
> also gives better error reporting as opposed to device failure.

We seem to be going in circles. You stated that no Fixes tag is needed
and that the previous code behaved correctly. However, as justification
for the change, you described it as providing more accurate and improved
reporting, which effectively sounds like a fix to me.

Thanks