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authorMark Brown <broonie@sirena.org.uk>2008-01-27 08:58:11 -0500
committerDavid S. Miller <davem@davemloft.net>2008-02-03 07:28:42 -0500
commit6344f0521aac9f93c312826216762f2185268390 (patch)
tree984ded12f15cb5ce71376ba6c6be3e72d3002427
parent35b5f6b1a82b5c586e0b24c711dc6ba944e88ef1 (diff)
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>
-rw-r--r--drivers/net/natsemi.c18
1 files changed, 2 insertions, 16 deletions
diff --git a/drivers/net/natsemi.c b/drivers/net/natsemi.c
index c329a4f5840..0a3e60418e5 100644
--- a/drivers/net/natsemi.c
+++ b/drivers/net/natsemi.c
@@ -203,22 +203,8 @@ skbuff at an offset of "+2", 16-byte aligning the IP header.
203IIId. Synchronization 203IIId. Synchronization
204 204
205Most operations are synchronized on the np->lock irq spinlock, except the 205Most operations are synchronized on the np->lock irq spinlock, except the
206performance critical codepaths: 206recieve and transmit paths which are synchronised using a combination of
207 207hardware descriptor ownership, disabling interrupts and NAPI poll scheduling.
208The rx process only runs in the interrupt handler. Access from outside
209the interrupt handler is only permitted after disable_irq().
210
211The rx process usually runs under the netif_tx_lock. If np->intr_tx_reap
212is set, then access is permitted under spin_lock_irq(&np->lock).
213
214Thus configuration functions that want to access everything must call
215 disable_irq(dev->irq);
216 netif_tx_lock_bh(dev);
217 spin_lock_irq(&np->lock);
218
219IV. Notes
220
221NatSemi PCI network controllers are very uncommon.
222 208
223IVb. References 209IVb. References
224 210