Re: [PATCH] net: macb: Change interrupt and napi enable order in open

[David Miller]

From: Harini Katakam <harini.katakam@xxxxxxxxxx>
Date: Tue, 7 May 2019 19:59:10 +0530

> Current order in open:
> -> Enable interrupts (macb_init_hw)
> -> Enable NAPI
> -> Start PHY
> 
> Sequence of RX handling:
> -> RX interrupt occurs
> -> Interrupt is cleared and interrupt bits disabled in handler
> -> NAPI is scheduled
> -> In NAPI, RX budget is processed and RX interrupts are re-enabled
> 
> With the above, on QEMU or fixed link setups (where PHY state doesn't
> matter), there's a chance macb RX interrupt occurs before NAPI is
> enabled. This will result in NAPI being scheduled before it is enabled.
> Fix this macb open by changing the order.
> 
> Fixes: ae1f2a56d273 ("net: macb: Added support for many RX queues")
> Signed-off-by: Harini Katakam <harini.katakam@xxxxxxxxxx>

Applied and queued up for -stable.