Re: [PATCH iwl] idpf: don't enable NAPI and interrupts prior to allocating Rx buffers

[Simon Horman]

On Fri, Apr 26, 2024 at 04:44:08PM +0200, Alexander Lobakin wrote:
> Currently, idpf enables NAPI and interrupts prior to allocating Rx
> buffers.
> This may lead to frame loss (there are no buffers to place incoming
> frames) and even crashes on quick ifup-ifdown. Interrupts must be
> enabled only after all the resources are here and available.
> Split interrupt init into two phases: initialization and enabling,
> and perform the second only after the queues are fully initialized.
> Note that we can't just move interrupt initialization down the init
> process, as the queues must have correct a ::q_vector pointer set
> and NAPI already added in order to allocate buffers correctly.
> Also, during the deinit process, disable HW interrupts first and
> only then disable NAPI. Otherwise, there can be a HW event leading
> to napi_schedule(), but the NAPI will already be unavailable.
> 
> Fixes: d4d558718266 ("idpf: initialize interrupts and enable vport")
> Reported-by: Michal Kubiak <michal.kubiak@xxxxxxxxx>
> Reviewed-by: Wojciech Drewek <wojciech.drewek@xxxxxxxxx>
> Signed-off-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>