Re: [PATCH net] bnxt_en: Write doorbell when linearizing skb fails

[Andy Gospodarek]

On Wed, Aug 26, 2026 at 2:00 AM Michael Chan <michael.chan@xxxxxxxxxxxx> wrote:
>
> On Tue, Aug 25, 2026 at 5:02 PM Joe Damato <joe@xxxxxxx> wrote:
> >
> > When the driver is handed a burst of packets, the doorbell is deferred
> > until the end. If the last packet has a huge number of frags, but fails
> > to linearize, the doorbell will not be written adding latency on TX for
> > any packets in the ring and holding their DMA mappings until the next
> > TX. Note that the queue is not stopped, so this issue would delay
> > pending BDs until the next TX.
> >
> > This issue was discovered by Sashiko and reading the code verifies that,
> > while unlikely, it is possible.
> >
> > Fix this by jumping to tx_free, which replicates the same pre-existing
> > logic but also writes the doorbell.
> >
> > Fixes: b91e82129400 ("bnxt_en: Linearize TX SKB if the fragments exceed the max")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Joe Damato <joe@xxxxxxx>
>
> Thanks.
> Reviewed-by: Michael Chan <michael.chan@xxxxxxxxxxxx>

Looks good to me, too.

Reviewed-by: Andy Gospodarek <gospo@xxxxxxxxxxxx>

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