Re: [PATCH net 1/3] mlxsw: core: Unregister EMAD trap using FORWARD action

[Simon Horman <horms@kernel.org>]

On Tue, Apr 16, 2024 at 12:24:14PM +0200, Petr Machata wrote:
> From: Ido Schimmel <idosch@nvidia.com>
> 
> The device's manual (PRM - Programmer's Reference Manual) classifies the
> trap that is used to deliver EMAD responses as an "event trap". Among
> other things, it means that the only actions that can be associated with
> the trap are TRAP and FORWARD (NOP).
> 
> Currently, during driver de-initialization the driver unregisters the
> trap by setting its action to DISCARD, which violates the above
> guideline. Future firmware versions will prevent such misuses by
> returning an error. This does not prevent the driver from working, but
> an error will be printed to the kernel log during module removal /
> devlink reload:
> 
> mlxsw_spectrum 0000:03:00.0: Reg cmd access status failed (status=7(bad parameter))
> mlxsw_spectrum 0000:03:00.0: Reg cmd access failed (reg_id=7003(hpkt),type=write)
> 
> Suppress the error message by aligning the driver to the manual and use
> a FORWARD (NOP) action when unregistering the trap.
> 
> Fixes: 4ec14b7634b2 ("mlxsw: Add interface to access registers and process events")
> Cc: Jiri Pirko <jiri@resnulli.us>
> Cc: Amit Cohen <amcohen@nvidia.com>
> Signed-off-by: Ido Schimmel <idosch@nvidia.com>
> Reviewed-by: Petr Machata <petrm@nvidia.com>
> Signed-off-by: Petr Machata <petrm@nvidia.com>

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