Re: [PATCH v3 6/7] libsas: add wait-complete support to sync discovery event

[John Garry]

On 10/07/2017 08:06, Yijing Wang wrote:

 static void sas_chain_event(int event, unsigned long *pending,
@@ -592,9 +596,9 @@ int sas_discover_event(struct asd_sas_port *port, enum 
discover_event ev)
 {
        struct sas_discovery *disc;

+       disc = &port->disc;
        if (!port)
                return 0;
-       disc = &port->disc;

        BUG_ON(ev >= DISC_NUM_EVENTS);

diff --git a/drivers/scsi/libsas/sas_expander.c 
b/drivers/scsi/libsas/sas_expander.c
index 570b2cb..9d26c28 1

I was just looking through the code and I noticed this, above. Is there 
a specific reason to move the NULL check, or was it modified accidentally?

I mean, if port is NULL I don't think we would get as far as checking it 
as we would have already de-referenced it.