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authorMark Brown <broonie@sirena.org.uk>2008-01-27 13:58:11 +0000
committerDavid S. Miller <davem@davemloft.net>2008-02-03 04:28:42 -0800
commit6344f0521aac9f93c312826216762f2185268390 (patch)
tree984ded12f15cb5ce71376ba6c6be3e72d3002427 /drivers/net
parent35b5f6b1a82b5c586e0b24c711dc6ba944e88ef1 (diff)
downloadop-kernel-dev-6344f0521aac9f93c312826216762f2185268390.zip
op-kernel-dev-6344f0521aac9f93c312826216762f2185268390.tar.gz
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>
Diffstat (limited to 'drivers/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 c329a4f..0a3e604 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.
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
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