[PATCH] 8250: Fix compiler warning

[PATCH] 8250: Fix compiler warning

[Kumar Gala]

drivers/tty/serial/8250.c: In function 'serial8250_shutdown':
drivers/tty/serial/8250.c:1775:19: warning: 'i' may be used uninitialized in this function

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
 drivers/tty/serial/8250.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c
index f2dfec8..44de222 100644
--- a/drivers/tty/serial/8250.c
+++ b/drivers/tty/serial/8250.c
@@ -1772,7 +1772,7 @@ static int serial_link_irq_chain(struct uart_8250_port *up)
 
 static void serial_unlink_irq_chain(struct uart_8250_port *up)
 {
-	struct irq_info *i;
+	struct irq_info *i = NULL;
 	struct hlist_node *n;
 	struct hlist_head *h;
 
-- 
1.7.3.4

Re: [PATCH] 8250: Fix compiler warning

[Alan Cox]

On Thu,  4 Aug 2011 03:13:01 -0500
Kumar Gala <galak@kernel.crashing.org> wrote:

> drivers/tty/serial/8250.c: In function 'serial8250_shutdown':
> drivers/tty/serial/8250.c:1775:19: warning: 'i' may be used uninitialized in this function

NAK, as with all the previous nacks of this.

Use a newer gcc - modern gcc gets it right.

Re: [PATCH] 8250: Fix compiler warning

[Kumar Gala]

On Aug 4, 2011, at 1:45 PM, Alan Cox wrote:

> On Thu,  4 Aug 2011 03:13:01 -0500
> Kumar Gala <galak@kernel.crashing.org> wrote:
> 
>> drivers/tty/serial/8250.c: In function 'serial8250_shutdown':
>> drivers/tty/serial/8250.c:1775:19: warning: 'i' may be used uninitialized in this function
> 
> NAK, as with all the previous nacks of this.
> 
> Use a newer gcc - modern gcc gets it right.

How modern? Building with a gcc 4.5.x

- k

Re: [PATCH] 8250: Fix compiler warning

[Maxin B John]

Hi Alan,

On Wed, Aug 10, 2011 at 5:01 PM, Kumar Gala <galak@kernel.crashing.org> wrote:
>
> On Aug 4, 2011, at 1:45 PM, Alan Cox wrote:
>
>> On Thu,  4 Aug 2011 03:13:01 -0500
>> Kumar Gala <galak@kernel.crashing.org> wrote:
>>
>>> drivers/tty/serial/8250.c: In function 'serial8250_shutdown':
>>> drivers/tty/serial/8250.c:1775:19: warning: 'i' may be used uninitialized in this function
>>
>> NAK, as with all the previous nacks of this.
>>
>> Use a newer gcc - modern gcc gets it right.

Can we use "uninitialized_var(x)" present in "linux/compiler-gcc.h"
in this scenario ?
ie:
struct irq_info *uninitialized_var(i);

Warm Regards,
Maxin

Re: [PATCH] 8250: Fix compiler warning

[Alan Cox]

> > Use a newer gcc - modern gcc gets it right.
> 
> How modern? Building with a gcc 4.5.x

4.5.x gets this right on x86 and I don't want to risk hiding a future bug
in that area of code with some mindless initialiser hacks.

(OTOH if you can figure a way to restructure that code a bit so its tidy,
clear and the compiler gets it right too ...)

Alan