From mboxrd@z Thu Jan  1 00:00:00 1970
From: gnomes@lxorguk.ukuu.org.uk (One Thousand Gnomes)
Date: Fri, 26 Feb 2016 00:06:51 +0000
Subject: [PATCH] serial: ifx6x60: avoid uninitialized variable use
In-Reply-To: <1456433283-3761559-1-git-send-email-arnd@arndb.de>
References: <1456433283-3761559-1-git-send-email-arnd@arndb.de>
Message-ID: <20160226000651.628e28fe@lxorguk.ukuu.org.uk>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Thu, 25 Feb 2016 21:47:57 +0100
Arnd Bergmann <arnd@arndb.de> wrote:

> gcc warns about a potential use of an uninitialized variable in this driver:
> 
> drivers/tty/serial/ifx6x60.c: In function 'ifx_spi_complete':
> drivers/tty/serial/ifx6x60.c:713:6: warning: 'more' may be used uninitialized in this function [-Wmaybe-uninitialized]
>    if (more || ifx_dev->spi_more || queue_length > 0 ||
> 
> Unlike a lot of other such warnings, this one is correct and describes
> an actual problem in the handling of the "IFX_SPI_HEADER_F" result code.
> 
> This appears to be a result from a restructuring of the driver that
> dates back to before it was merged in the kernel, so it's impossible
> to know where it went wrong. I also don't know what that result code
> means, so I have no idea if setting 'more' to zero is the correct
> solution, but at least it makes the behavior reproducible rather than
> depending on whatever happens to be on the kernel stack.

Would it not be far simpler just to set more = 0 at the top of
ifx_spi_complete ?