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| author | Haiyang Zhang <haiyangz@microsoft.com> | 2016-03-04 15:07:43 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-03-07 15:37:50 -0500 |
| commit | d66ab51442211158b677c2f12310c314d9587f74 (patch) | |
| tree | 55f26b6289dea8fb618aa81fad92f89c26720530 | |
| parent | ab825adbaaec14b7bcfd7265da3439e6e96113c1 (diff) | |
| download | linux-d66ab51442211158b677c2f12310c314d9587f74.tar.gz linux-d66ab51442211158b677c2f12310c314d9587f74.tar.bz2 linux-d66ab51442211158b677c2f12310c314d9587f74.zip | |
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>
| -rw-r--r-- | drivers/net/hyperv/rndis_filter.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c index a37bbda37ffa..47d07c576a34 100644 --- a/drivers/net/hyperv/rndis_filter.c +++ b/drivers/net/hyperv/rndis_filter.c @@ -1175,22 +1175,18 @@ int rndis_filter_device_add(struct hv_device *dev, ret = rndis_filter_set_rss_param(rndis_device, net_device->num_chn); /* - * Wait for the host to send us the sub-channel offers. + * Set the number of sub-channels to be received. */ spin_lock_irqsave(&net_device->sc_lock, flags); sc_delta = num_rss_qs - (net_device->num_chn - 1); net_device->num_sc_offered -= sc_delta; spin_unlock_irqrestore(&net_device->sc_lock, flags); - while (net_device->num_sc_offered != 0) { - t = wait_for_completion_timeout(&net_device->channel_init_wait, 10*HZ); - if (t == 0) - WARN(1, "Netvsc: Waiting for sub-channel processing"); - } out: if (ret) { net_device->max_chn = 1; net_device->num_chn = 1; + net_device->num_sc_offered = 0; } return 0; /* return 0 because primary channel can be used alone */ @@ -1204,6 +1200,17 @@ void rndis_filter_device_remove(struct hv_device *dev) { struct netvsc_device *net_dev = hv_get_drvdata(dev); struct rndis_device *rndis_dev = net_dev->extension; + unsigned long t; + + /* If not all subchannel offers are complete, wait for them until + * completion to avoid race. + */ + while (net_dev->num_sc_offered > 0) { + t = wait_for_completion_timeout(&net_dev->channel_init_wait, + 10 * HZ); + if (t == 0) + WARN(1, "Netvsc: Waiting for sub-channel processing"); + } /* Halt and release the rndis device */ rndis_filter_halt_device(rndis_dev); |