K 10
svn:author
V 4
manu
K 8
svn:date
V 27
2017-11-18T20:42:48.647843Z
K 7
svn:log
V 685
if_awg: mark the first tx descriptor as ready only after all the other tx descriptors are set up

In a multi segment frame, if the first tx descriptor is marked with TX_DESC_CTL
but not all tx descriptors for the other segments in the frame are set up,
the TX DMA may transmit an incomplete frame.
To prevent this, set TX_DESC_CTL for the first tx descriptor only when done
with all the other segments.

Also, don't bother cleaning transmitted tx descriptors since TX_DESC_CTL
is cleared for them by the hardware and they will be reprogrammed before
TX_DESC_CTL is reenabled for them.

Submitted by:	Guy Yur <guyyur@gmail.com>
Differential Revision:	https://reviews.freebsd.org/D13030

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