Re: [PATCH 0/4] Pull request for 'ipg-fixes' branch

[linux@horizon.com]

Thank you very much, this appears to work.

> The driver is still a POMS but it seems better now.

I notice that the vendor-supplied driver doesn't have these bugs.
Now, it does have a bug in that it doesn't have an "is this
interrupt for me?" test at all (and always returns "I handled it"),
but the bypass and its locking screwups are a later addition.

The same with the sp->rx_current bugs.  The original loop which used
rx_current as the loop iteration variable wasn't great style, precisely
because it hides the interaction that someone's "optimization" broke,
but I don't want to blame the vendor for things they didn't do.

Would you be interested in some cleanup patches?  In particular, I think I
can get rid of tx->lock entirely, or at least take it off the fast path.
All it's protecting is the write to sp->tx_current, and a few judicious
memory barriers can deal with that.


(Oh, another BUG: the sp->ResetCurrentTFD logic in hard_start_xmit is
just plain broken.  It writes the new data to entry 0, then increments
sp->tx_current just like usual.  THAT isn't in the vendor driver that
I see, either.)