[PATCH 06/10] staging: unisys: visornic: prevent hang doing 'modprobe -r visornic'

David Kershner david.kershner at unisys.com
Wed Feb 1 22:38:58 UTC 2017


From: Tim Sell <Timothy.Sell at unisys.com>

A stray+extraneous 'netif_napi_add()' that we were doing in
visornic_probe() was causing havoc when we got into visornic_remove(),
called during 'modprobe -r visornic'. The symptom was a processor busy-wait
loop on the modprobe process, which '/proc/<pid>/stack' would show looping
doing napi things.

Presumably the stray line got there as a result of some merging snafoo, and
has been deleted to fix the problem. With this patch 'modprobe -r visornic'
and a subsequent 'modprobe visornic' both complete successfully, and result
in an operational network.

Signed-off-by: Tim Sell <Timothy.Sell at unisys.com>
Signed-off-by: David Kershner <david.kershner at unisys.com>
---
 drivers/staging/unisys/visornic/visornic_main.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/staging/unisys/visornic/visornic_main.c b/drivers/staging/unisys/visornic/visornic_main.c
index c44c430..d8f5eca 100644
--- a/drivers/staging/unisys/visornic/visornic_main.c
+++ b/drivers/staging/unisys/visornic/visornic_main.c
@@ -1802,7 +1802,7 @@ static int visornic_probe(struct visor_device *dev)
 
 	/* TODO: Setup Interrupt information */
 	/* Let's start our threads to get responses */
-	netif_napi_add(netdev, &devdata->napi, visornic_poll, 64);
+	netif_napi_add(netdev, &devdata->napi, visornic_poll, NAPI_WEIGHT);
 
 	setup_timer(&devdata->irq_poll_timer, poll_for_irq,
 		    (unsigned long)devdata);
@@ -1832,9 +1832,6 @@ static int visornic_probe(struct visor_device *dev)
 		goto cleanup_napi_add;
 	}
 
-	/* Let's start our threads to get responses */
-	netif_napi_add(netdev, &devdata->napi, visornic_poll, NAPI_WEIGHT);
-
 	/* Note: Interrupts have to be enable before the while
 	 * loop below because the napi routine is responsible for
 	 * setting enab_dis_acked
-- 
git-series 0.9.1


More information about the devel mailing list