Commit 6b81b193 authored by Haiyang Zhang's avatar Haiyang Zhang Committed by David S. Miller
Browse files

hv_netvsc: Fix napi reschedule while receive completion is busy 



If out ring is full temporarily and receive completion cannot go out,
we may still need to reschedule napi if certain conditions are met.
Otherwise the napi poll might be stopped forever, and cause network
disconnect.

Fixes: 7426b1a5 ("netvsc: optimize receive completions")
Signed-off-by: default avatarStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a2ec9d14

drivers/net/hyperv/netvsc.c

+10 −7
Original line number Diff line number Diff line
@@ -1274,6 +1274,7 @@ int netvsc_poll(struct napi_struct *napi, int budget) 
	struct hv_device *device = netvsc_channel_to_device(channel);

	struct net_device *ndev = hv_get_drvdata(device);

	int work_done = 0;

	int ret;



	/* If starting a new interval */

	if (!nvchan->desc)
@@ -1285,16 +1286,18 @@ int netvsc_poll(struct napi_struct *napi, int budget) 
		nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);

	}



	/* If send of pending receive completions suceeded

	 *   and did not exhaust NAPI budget this time

	/* Send any pending receive completions */

	ret = send_recv_completions(ndev, net_device, nvchan);



	/* If it did not exhaust NAPI budget this time

	 *  and not doing busy poll

	 * then re-enable host interrupts

	 *     and reschedule if ring is not empty.

	 *  and reschedule if ring is not empty

	 *   or sending receive completion failed.

	 */

	if (send_recv_completions(ndev, net_device, nvchan) == 0 &&

	    work_done < budget &&

	if (work_done < budget &&

	    napi_complete_done(napi, work_done) &&

	    hv_end_read(&channel->inbound) &&

	    (ret || hv_end_read(&channel->inbound)) &&

	    napi_schedule_prep(napi)) {

		hv_begin_read(&channel->inbound);

		__napi_schedule(napi);

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