[vortex] 3C905CX, 2.2.18, Dell Dimension 4100 (P933) ReceiveFailure Fix / Inquiry

[Bogdan Costescu]

On Wed, 17 Jan 2001, Joe Rouvier wrote:

> If it's rare for a device to take more than one PCI transaction to do
> something, do you think the ~30000 transaction count for RxReset on the
> 3c905cx means the current driver doesn't init the card correctly?  Or is
> the new chip just slow on that command?

The latter. For some reason, the 3Com engineers decided that the RxReset
command should take longer. 3Com's driver (3c90x) waits up to 1 second for
_any_ command to complete (I'm talking here only about the commands that
need to be waited for); their Windows driver does the same.

> But the longer loop is only used on TxReset, RxReset, TotalReset,
> DownStall and RxDiscard.  Aren't these commands sent very rarely?
> (referring specifically to the 2.2.19-pre2 driver with Adam M's
> wait_for_completion() changes)

Not all commands need to be waited for. For example, when a DownStall
command comes, the NIC might just be in the middle of the download
procedure, so it has to finish this first and then go into the stall-ed
state. The opposite command (DownUnstall) doesn't have any such constraint
and is effective immediately.
The *Reset commands are supposed to be sent very rarely, indeed. But
DownStall is sent for every queued Tx packet, which is very often (at
least in the non-polling mode).

> I recently purchased 6 of the Dells with this card.  We will be writing
> networking software on 'em.  This tends to make having a reliable NIC
> kind of nice.  Should I yank the cards and get something else?  If so,
> any recommendations?

I don't personally have such cards, but from the reports up to now, it
seems like the RxReset timing is the only thing which has changed w.r.t.
the older 905C cards - which I have and are very reliable.

Sincerely,

Bogdan Costescu

IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen
Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY
Telephone: +49 6221 54 8869, Telefax: +49 6221 54 8868
E-mail: Bogdan.Costescu@IWR.Uni-Heidelberg.De