From a1b43eddaec5a3fea55e1581caf217abda2d3147 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 21 Jul 2016 21:28:34 +0200 Subject: [PATCH] net/ncsi: avoid maybe-uninitialized warning gcc-4.9 and higher warn about the newly added NSCI code: net/ncsi/ncsi-manage.c: In function 'ncsi_process_next_channel': net/ncsi/ncsi-manage.c:1003:2: error: 'old_state' may be used uninitialized in this function [-Werror=maybe-uninitialized] The warning is a false positive and therefore harmless, but it would be good to avoid it anyway. I have determined that the barrier in the spin_unlock_irqsave() is what confuses gcc to the point that it cannot track whether the variable was unused or not. This rearranges the code in a way that makes it obvious to gcc that old_state is always initialized at the time of use, functionally this should not change anything. Signed-off-by: Arnd Bergmann Acked-by: Gavin Shan Signed-off-by: David S. Miller --- net/ncsi/ncsi-manage.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c index d627a39ddcd0..ef017b871857 100644 --- a/net/ncsi/ncsi-manage.c +++ b/net/ncsi/ncsi-manage.c @@ -982,23 +982,18 @@ int ncsi_process_next_channel(struct ncsi_dev_priv *ndp) spin_lock_irqsave(&ndp->lock, flags); nc = list_first_or_null_rcu(&ndp->channel_queue, struct ncsi_channel, link); - if (nc) { - old_state = xchg(&nc->state, NCSI_CHANNEL_INVISIBLE); - list_del_init(&nc->link); + if (!nc) { + spin_unlock_irqrestore(&ndp->lock, flags); + goto out; } + + old_state = xchg(&nc->state, NCSI_CHANNEL_INVISIBLE); + list_del_init(&nc->link); + spin_unlock_irqrestore(&ndp->lock, flags); ndp->active_channel = nc; - ndp->active_package = nc ? nc->package : NULL; - if (!nc) { - if (ndp->flags & NCSI_DEV_RESHUFFLE) { - ndp->flags &= ~NCSI_DEV_RESHUFFLE; - return ncsi_choose_active_channel(ndp); - } - - ncsi_report_link(ndp, false); - return -ENODEV; - } + ndp->active_package = nc->package; switch (old_state) { case NCSI_CHANNEL_INACTIVE: @@ -1017,6 +1012,17 @@ int ncsi_process_next_channel(struct ncsi_dev_priv *ndp) } return 0; + +out: + ndp->active_channel = NULL; + ndp->active_package = NULL; + if (ndp->flags & NCSI_DEV_RESHUFFLE) { + ndp->flags &= ~NCSI_DEV_RESHUFFLE; + return ncsi_choose_active_channel(ndp); + } + + ncsi_report_link(ndp, false); + return -ENODEV; } #if IS_ENABLED(CONFIG_IPV6) -- 2.20.1