linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Stephen Rothwell <sfr@canb.auug.org.au>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linux PPC Development List <linuxppc-dev@lists.ozlabs.org>,
	Linux Next Mailing List <linux-next@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Jiri Slaby <jslaby@suse.com>,
	Michal Simek <michal.simek@xilinx.com>,
	Linux Serial List <linux-serial@vger.kernel.org>,
	Linus ARM List <linux-arm-kernel@lists.infradead.org>
Subject: xilinx_uartps.c: suppress "may be used uninitialised" warning
Date: Wed, 31 Jul 2019 16:05:57 +1000	[thread overview]
Message-ID: <20190731160557.6a09c3e1@canb.auug.org.au> (raw)

[-- Attachment #1: Type: text/plain, Size: 2311 bytes --]

From 31753a44c62c4fdf6e8a72994ae6861dbde49c11 Mon Sep 17 00:00:00 2001
From: Stephen Rothwell <sfr@canb.auug.org.au>
Date: Wed, 31 Jul 2019 16:00:52 +1000
Subject: [PATCH] xilinx_uartps.c: suppress "may be used uninitialised" warning

A powerpc allyesconfig build produces this warning:

In file included from include/linux/radix-tree.h:16,
                 from include/linux/idr.h:15,
                 from include/linux/kernfs.h:13,
                 from include/linux/sysfs.h:16,
                 from include/linux/kobject.h:20,
                 from include/linux/device.h:16,
                 from include/linux/platform_device.h:13,
                 from drivers/tty/serial/xilinx_uartps.c:16:
drivers/tty/serial/xilinx_uartps.c: In function 'cdns_uart_console_write':
include/linux/spinlock.h:288:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]
   _raw_spin_unlock_irqrestore(lock, flags); \
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/tty/serial/xilinx_uartps.c:1197:16: note: 'flags' was declared here
  unsigned long flags;
                ^~~~~

It looks like gcc just can't track the relationship between "locked"
and "flags", and it is obvious that "flags" won't be used when "locked"
is zero, so the simplest thing is to initialise flags.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
 drivers/tty/serial/xilinx_uartps.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

This has been like this for a very long time, but this is now one of
the few remaining warnings produced by the powerpc allyesconfig build,
so it would be good to get rid of it.

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index f145946f659b..da4563aaaf5c 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -1194,7 +1194,7 @@ static void cdns_uart_console_write(struct console *co, const char *s,
 				unsigned int count)
 {
 	struct uart_port *port = console_port;
-	unsigned long flags;
+	unsigned long flags = 0;
 	unsigned int imr, ctrl;
 	int locked = 1;
 
-- 
2.22.0

-- 
Cheers,
Stephen Rothwell

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

                 reply	other threads:[~2019-07-31  6:06 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190731160557.6a09c3e1@canb.auug.org.au \
    --to=sfr@canb.auug.org.au \
    --cc=gregkh@linuxfoundation.org \
    --cc=jslaby@suse.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-next@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=michal.simek@xilinx.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).