Re: [PATCH net-next v2] net: thunderx: Fix transmit queue timeout issue

From: David Miller
Date: Fri Dec 02 2016 - 13:33:17 EST


From: sunil.kovvuri@xxxxxxxxx
Date: Thu, 1 Dec 2016 18:24:28 +0530

> From: Sunil Goutham <sgoutham@xxxxxxxxxx>
>
> Transmit queue timeout issue is seen in two cases
> - Due to a race condition btw setting stop_queue at xmit()
> and checking for stopped_queue in NAPI poll routine, at times
> transmission from a SQ comes to a halt. This is fixed
> by using barriers and also added a check for SQ free descriptors,
> incase SQ is stopped and there are only CQE_RX i.e no CQE_TX.
> - Contrary to an assumption, a HW errata where HW doesn't stop transmission
> even though there are not enough CQEs available for a CQE_TX is
> not fixed in T88 pass 2.x. This results in a Qset error with
> 'CQ_WR_FULL' stalling transmission. This is fixed by adjusting
> RXQ's RED levels for CQ level such that there is always enough
> space left for CQE_TXs.
>
> Signed-off-by: Sunil Goutham <sgoutham@xxxxxxxxxx>
> ---
> v2: As suggested by David, replaced netif_tx_start_queue with
> netif_tx_wake_queue.

Applied, thanks.