hv_netvsc: Move subchannel waiting to rndis_filter_device_remove()
authorHaiyang Zhang <haiyangz@microsoft.com>
Fri, 4 Mar 2016 23:07:43 +0000 (15:07 -0800)
committerDavid S. Miller <davem@davemloft.net>
Mon, 7 Mar 2016 20:37:50 +0000 (15:37 -0500)
commitd66ab51442211158b677c2f12310c314d9587f74
tree55f26b6289dea8fb618aa81fad92f89c26720530
parentab825adbaaec14b7bcfd7265da3439e6e96113c1
hv_netvsc: Move subchannel waiting to rndis_filter_device_remove()

During hot add, vmbus_device_register() is called from vmbus_onoffer(), on
the same workqueue as the subchannel offer message work-queue, so
subchannel offer won't be processed until the vmbus_device_register()/...
/netvsc_probe() is done.
Also, vmbus_device_register() is called with channel_mutex locked, which
prevents subchannel processing too. So the "waiting for sub-channel
processing" will not success in hot add case. But, in usual module loading,
the netvsc_probe() is called from different code path, and doesn't fail.

This patch resolves the deadlock during NIC hot-add, and speeds up NIC
loading time.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/hyperv/rndis_filter.c