Re: [PATCH net-next 15/15] mlxsw: pci: Store DQ pointer as part of CQ structure

[Simon Horman <horms@kernel.org>]

On Tue, Apr 02, 2024 at 03:54:28PM +0200, Petr Machata wrote:
> From: Amit Cohen <amcohen@nvidia.com>
> 
> Currently, for each completion, we check the number of descriptor queue
> and take it via mlxsw_pci_{sdq,rdq}_get(). This is inefficient, the
> DQ should be the same for all the completions in CQ, as each CQ handles
> only one DQ - SDQ or RDQ. This mapping is handled as part of DQ
> initialization via mlxsw_cmd_mbox_sw2hw_dq_cq_set().
> 
> Instead, as part of DQ initialization, set DQ pointer in the appropriate
> CQ structure. When we handle completions, warn in case that the DQ number
> that we expect is different from the number we get in the CQE. Call
> WARN_ON_ONCE() only after checking the value, to avoid calling this method
> for each completion.
> 
> Signed-off-by: Amit Cohen <amcohen@nvidia.com>
> Reviewed-by: Ido Schimmel <idosch@nvidia.com>
> Signed-off-by: Petr Machata <petrm@nvidia.com>

Reviewed-by: Simon Horman <horms@kernel.org>