staging: unisys: visornic: prevent hang doing 'modprobe -r visornic'
authorTim Sell <Timothy.Sell@unisys.com>
Wed, 1 Feb 2017 22:38:58 +0000 (17:38 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 2 Feb 2017 12:10:49 +0000 (13:10 +0100)
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@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/unisys/visornic/visornic_main.c

index c44c430..d8f5eca 100644 (file)
@@ -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