Why don't you disable the interrupt after the first TX_done interrupt
(no RX pending, no RX done)? Maybe you can printk "forcedeth device [x,y] does
not need timer interrupts, please send this line to you@example.org", too.
Maybe you can even disable it if no TX is to be done.
OTOH, this fix is available, it's possibly the best to use it for now.
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