Re: NIU driver: Sun x8 Express Quad Gigabit Ethernet Adapter

From: Jesper Dangaard Brouer
Date: Wed Nov 12 2008 - 16:32:00 EST



Hi Google,

On Wed, 12 Nov 2008, David Miller wrote:

Guess what that does? The packet counters live in the upper
32-bits and the MARK bits live in the lower 32-bits of the
TX_CS register.

So it first reads the packet counters, and as a side effect that
clears the MARK bits in the TX_CS register. So when we read the lower
32-bits the MARK bits are always seen as zero.

For the thorough reader, the TX_CS Transmit Control and Status register is described in table 26-15 page 761-762 in the PDF document titled: "UltraSPARC T2 supplement to UltraSPARC architecture 2007", downloadable from: http://opensparc-t2.sunsource.net/specs/UST2-UASuppl-current-draft-HP-EXT.pdf

Cheers,
Jesper Brouer

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