Re: [PATCH net-next] net/ncsi: avoid maybe-uninitialized warning

[Gavin Shan]

On Thu, Jul 21, 2016 at 09:28:34PM +0200, Arnd Bergmann wrote:
>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 <arnd@xxxxxxxx>

Acked-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>