Re: [PATCH net-next 12/14] r8152: replace netif_rx withnetif_receive_skb

[Francois Romieu]

hayeswang <hayeswang@xxxxxxxxxxx> :
>  Francois Romieu [mailto:romieu@xxxxxxxxxxxxx] 
> > Hayes Wang <hayeswang@xxxxxxxxxxx> :
> > > Replace netif_rx with netif_receive_skb to avoid disabling irq frequently
> > > for increasing the efficiency.
> > 
> > read_bulk_callback is issued in irq context. It could thus use plain
> > spin_lock / spin_unlock instead of the irq disabling version.
> 
> The rx_bottom() is called in tasklet, so I just think I could use
> netif_receive_skb directly. The netif_rx seems to queue the packet,
> and local_irq_disable() would be called before dequeuing the skb.

The change in rx_bottom is fine. My point is about read_bulk_callback.

rx_bottom races with read_bulk_callback. rx_bottom is issued in
tasklet (softirq) context. read_bulk_callback is issued in irq
context, with irq disabled. read_bulk_callback does not need to
disable irq itself and could go with spin_lock in place of
spin_lock_irqsave (rx_bottom can't, of course).

-- 
Ueimor
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