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Ben Hutchings 8f4cccbbd9 net: Set device operstate at registration time 
The operstate of a device is initially IF_OPER_UNKNOWN and is updated
asynchronously by linkwatch after each change of carrier state
reported by the driver.  The default carrier state of a net device is
on, and this will never be changed on drivers that do not support
carrier detection, thus the operstate remains IF_OPER_UNKNOWN.

For devices that do support carrier detection, the driver must set the
carrier state to off initially, then poll the hardware state when the
device is opened.  However, we must not activate linkwatch for a
unregistered device, and commit b473001 ('net: Do not fire linkwatch
events until the device is registered.') ensured that we don't.  But
this means that the operstate for many devices that support carrier
detection remains IF_OPER_UNKNOWN when it should be IF_OPER_DOWN.

The same issue exists with the dormant state.

The proper initialisation sequence, avoiding a race with opening of
the device, is:

        rtnl_lock();
        rc = register_netdevice(dev);
        if (rc)
                goto out_unlock;
        netif_carrier_off(dev); /* or netif_dormant_on(dev) */
        rtnl_unlock();

but it seems silly that this should have to be repeated in so many
drivers.  Further, the operstate seen immediately after opening the
device may still be IF_OPER_UNKNOWN due to the asynchronous nature of
linkwatch.

Commit 22604c8 ('net: Fix for initial link state in 2.6.28') attempted
to fix this by setting the operstate synchronously, but it was
reverted as it could lead to deadlock.

This initialises the operstate synchronously at registration time
only.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 		2012-08-24 12:46:13 -04:00
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acpi Merge branches 'delete-gts-bfs', 'misc', 'novell-bugzilla-757888-numa' and 'osc-pcie' into base 2012-08-03 00:31:23 -04:00
asm-generic mutex: Place lock in contended state after fastpath_lock failure 2012-08-13 18:46:54 +02:00
crypto
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drm drm/radeon/kms: implement timestamp userspace query (v2) 2012-08-13 10:50:56 -04:00
keys
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linux net: Set device operstate at registration time 2012-08-24 12:46:13 -04:00
math-emu
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media [media] v4l2: add core support for the new VIDIOC_ENUM_FREQ_BANDS ioctl 2012-07-30 20:23:05 -03:00
memory
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misc
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mtd
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net packet: fix broken build. 2012-08-23 09:29:45 -07:00
pcmcia
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ras
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rdma Merge branches 'cma', 'cxgb4', 'misc', 'mlx4-sriov', 'mlx-cleanups', 'ocrdma' and 'qib' into for-linus 2012-07-22 23:26:17 -07:00
rxrpc
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scsi Merge branch 'master' [vanilla Linus master] into libata-dev.git/upstream 2012-07-25 15:58:48 -04:00
sound ASoC: Additional updates for 3.6 2012-08-20 21:26:04 +02:00
target target: Allow for target_submit_cmd() returning errors 2012-07-17 17:05:05 -07:00
trace Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-08-03 10:57:20 -07:00
video video: da8xx-fb: configure FIFO threshold to reduce underflow errors 2012-07-29 01:11:09 +00:00
xen xen PVonHVM: move shared_info to MMIO before kexec 2012-07-19 15:52:05 -04:00
Kbuild
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