natsemi: Update locking documentation
The documentation regarding synchronisation at the head of the natsemi
driver was badly bitrotted so replace it with a general statement about
the techniques used which is less likely to bitrot.
Also remove the note saying these chips are uncommon - it makes little
difference but they were used in a number of laptops and at least one mass
market PCI ethernet card.
Signed-off-by: Mark Brown <broonie@sirena.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/natsemi.c b/drivers/net/natsemi.c
index c329a4f..0a3e604 100644
--- a/drivers/net/natsemi.c
+++ b/drivers/net/natsemi.c
@@ -203,22 +203,8 @@
IIId. Synchronization
Most operations are synchronized on the np->lock irq spinlock, except the
-performance critical codepaths:
-
-The rx process only runs in the interrupt handler. Access from outside
-the interrupt handler is only permitted after disable_irq().
-
-The rx process usually runs under the netif_tx_lock. If np->intr_tx_reap
-is set, then access is permitted under spin_lock_irq(&np->lock).
-
-Thus configuration functions that want to access everything must call
- disable_irq(dev->irq);
- netif_tx_lock_bh(dev);
- spin_lock_irq(&np->lock);
-
-IV. Notes
-
-NatSemi PCI network controllers are very uncommon.
+recieve and transmit paths which are synchronised using a combination of
+hardware descriptor ownership, disabling interrupts and NAPI poll scheduling.
IVb. References