e1000e: stop unnecessary polling when using msi-x
authorAndy Gospodarek <andy@greyhouse.net>
Thu, 18 Jun 2009 11:57:37 +0000 (11:57 +0000)
committerDavid S. Miller <davem@davemloft.net>
Fri, 19 Jun 2009 08:12:51 +0000 (01:12 -0700)
commit679e8a0f0ae3333e94b1d374d07775fce9066025
treed24d7b1f37f8f33599841b51b9aef0c13e57f0e4
parent68924920cb457ac44b14ca38343954bdcee046fc
e1000e: stop unnecessary polling when using msi-x

The last hunk of this commit:

    commit 12d04a3c12b420f23398b4d650127642469a60a6
    Author: Alexander Duyck <alexander.h.duyck@intel.com>
    Date:   Wed Mar 25 22:05:03 2009 +0000

        e1000e: commonize tx cleanup routine to match e1000 & igb

changed the logic for determining if we should call napi_complete or
not at then end of a napi poll.

If the NIC is using MSI-X with no work to do in ->poll, net_rx_action
can just spin indefinitely on older kernels and for 2 jiffies on newer
kernels since napi_complete is never called and budget isn't
decremented.

Discovered and verified while testing driver backport to an older
kernel.

Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/e1000e/netdev.c