On 08/01/2017 04:55 PM, Florian Fainelli wrote:
This is not specific to your EMAC, a lot of adapters have this problem
actually.
I wonder if it would make sense to reach for a broader solution where we
could have a networking stack panic/oops notifier which will actively
clean up the active network devices' RX queue(s) and if tx_pause was
enabled, disable it. We could have drivers announce themselves as
needing this either via NETIF_F_* feature bit or some other private flag.
Unfortunately, the problem occurs only when Linux hangs, to the point
where the driver's interrupt handlers are blocked. The RX queue is 256
entries, and the processor has 48 cores, so the EMAC is never going to
send pause frames in any real-world situation.
The only time I've seen pause frames sent out is in the lab when I halt
the cores with a hardware debugger, and only if I have enough network
traffic that the EMAC picks up.
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