[vortex-bug] DPD FSH for Cyclone/Tornado

[Bogdan Costescu]

On Thu, 18 May 2000, Andrew Morton wrote:

> Bogdan Costescu wrote:
> > ...
> > On the netdev list I learned that hard_start_xmit (which is
> > boomerang_start_xmit in this case) is externally protected WRT
> > re-entrance.
> In 2.3 only, I believe.  The netdevice.xmit_lock is not present in 2.2.

I thought that the Alexey's answer was for both, but I might be wrong...
Anyway, if 2.2 has no xmit_lock (or any other way of locking start_xmit),
then tbusy should be in fact something like in_start_xmit that would only
be set at the beginning and cleared at the exit from start_xmit. The
current code also clears it in vortex_tx_timeout (which might be OK) and
vortex_interrupt (which might not be OK because it's async WRT
start_xmit).

And if the compatibility with older kernels that do not have xmit_lock or
similar is a concern, would it be feasible to #ifdef usage of tbusy?

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