Subject: Re: [PATCH net-next] net: thunderbolt: Clear finished Tx frame bus address in tbnet_tx_callback()

From: 'Mika Westerberg' <[email-masked]>
Date: Mon, 20 Nov 2017 17:05:16 +0200

On Mon, Nov 20, 2017 at 02:46:53PM +0000, David Laight wrote:
> > There does not seem to be a way to mark DMA address invalid in a driver
> > so we probably need to add a flag to struct tbnet_frame instead.
> 
> Can you use the length?

Unfortunately no because size is 12-bit field in struct ring_frame and 0
means 4096 bytes.