[PATCH v2] net: arc/emac: Move arc_emac_tx_clean() into arc_emac_tx() and disable tx interrut

[David Miller]

From: Caesar Wang <wxt at rock-chips.com>
Date: Fri,  6 May 2016 20:19:16 +0800

> Doing tx_clean() inside poll() may scramble the tx ring buffer if
> tx() is running. This will cause tx to stop working, which can be
> reproduced by simultaneously downloading two large files at high speed.
> 
> Moving tx_clean() into tx() will prevent this. And tx interrupt is no
> longer needed now.

TX completion work is always recommended to be done in the ->poll()
handler.

Fix the race or whatever bug there is rather than working around it,
and regressing the driver, by handling TX completion in the interrupt
handler.

Thanks.