Re: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller

From: Måns Rullgård
Date: Wed Nov 11 2015 - 14:09:25 EST

David Miller <davem@xxxxxxxxxxxxx> writes:

> From: Måns Rullgård <mans@xxxxxxxxx>
> Date: Wed, 11 Nov 2015 18:25:05 +0000
>> If the TX DMA channel is idle when start_xmit is called, it can be
>> started immediately. Checking the DMA status and starting it if
>> idle has to be done atomically somehow.
> ->ndo_start_xmit() is guaranteed to be invoked atomically, protected
> by the TX queue spinlock.

Yes, but the DMA needs to be restarted from some other context if it was
busy when start_xmit checked.

Måns Rullgård
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