2009-04-12 12:24:52

by helight.xu

[permalink] [raw]
Subject: [PATCH] fix a warning on drivers/infiniband/hw/nes/nes_cm.c:862:

Fix this warning:
drivers/infiniband/hw/nes/nes_cm.c:862: warning: unused variable ‘tmp_addr’

the 'tmp_addr' is defined for debug, so it should be defined in
CONFIG_INFINIBAND_NES_DEBUG


>From 5f67884bcda5450807dcd080378d829628e4db1c Mon Sep 17 00:00:00 2001
From: Zhenwen Xu <[email protected]>
Date: Sun, 12 Apr 2009 20:12:18 +0800
Subject: [PATCH] fix a warning on drivers/infiniband/hw/nes/nes_cm.c:862:

Signed-off-by: Zhenwen Xu <[email protected]>
---
drivers/infiniband/hw/nes/nes_cm.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/infiniband/hw/nes/nes_cm.c b/drivers/infiniband/hw/nes/nes_cm.c
index dbd9a75..1bad93b 100644
--- a/drivers/infiniband/hw/nes/nes_cm.c
+++ b/drivers/infiniband/hw/nes/nes_cm.c
@@ -854,8 +854,9 @@ static struct nes_cm_listener *find_listener(struct nes_cm_core *cm_core,
{
unsigned long flags;
struct nes_cm_listener *listen_node;
+#ifdef CONFIG_INFINIBAND_NES_DEBUG
__be32 tmp_addr = cpu_to_be32(dst_addr);
-
+#endif
/* walk list and find cm_node associated with this session ID */
spin_lock_irqsave(&cm_core->listen_list_lock, flags);
list_for_each_entry(listen_node, &cm_core->listen_list.list, list) {
--
1.5.6.5

--
---------------------------------
Zhenwen Xu - Open and Free
Home Page: http://zhwen.org
My Studio: http://dim4.cn


2009-04-15 21:36:17

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH] fix a warning on drivers/infiniband/hw/nes/nes_cm.c:862:

On Sun, 12 Apr 2009 20:23:17 +0800
Zhenwen Xu <[email protected]> wrote:

> Fix this warning:
> drivers/infiniband/hw/nes/nes_cm.c:862: warning: unused variable ___tmp_addr___
>
> the 'tmp_addr' is defined for debug, so it should be defined in
> CONFIG_INFINIBAND_NES_DEBUG
>
>
> >From 5f67884bcda5450807dcd080378d829628e4db1c Mon Sep 17 00:00:00 2001
> From: Zhenwen Xu <[email protected]>
> Date: Sun, 12 Apr 2009 20:12:18 +0800
> Subject: [PATCH] fix a warning on drivers/infiniband/hw/nes/nes_cm.c:862:
>
> Signed-off-by: Zhenwen Xu <[email protected]>
> ---
> drivers/infiniband/hw/nes/nes_cm.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/infiniband/hw/nes/nes_cm.c b/drivers/infiniband/hw/nes/nes_cm.c
> index dbd9a75..1bad93b 100644
> --- a/drivers/infiniband/hw/nes/nes_cm.c
> +++ b/drivers/infiniband/hw/nes/nes_cm.c
> @@ -854,8 +854,9 @@ static struct nes_cm_listener *find_listener(struct nes_cm_core *cm_core,
> {
> unsigned long flags;
> struct nes_cm_listener *listen_node;
> +#ifdef CONFIG_INFINIBAND_NES_DEBUG
> __be32 tmp_addr = cpu_to_be32(dst_addr);
> -
> +#endif
> /* walk list and find cm_node associated with this session ID */
> spin_lock_irqsave(&cm_core->listen_list_lock, flags);
> list_for_each_entry(listen_node, &cm_core->listen_list.list, list) {

eek, an ugly ifdef. And we can't just remove tmp_addr because
printk(%p) wants to be passed an address rather than a value.

It'd be nice if we had a handy macro to squish the warning, like
uninitialized_var.

As it happens, uninitialized_var() _does_ suppress the unused-var warning:

--- a/drivers/infiniband/hw/nes/nes_cm.c~drivers-infiniband-hw-nes-nes_cmc-fix-unused-var-warning-cleanup
+++ a/drivers/infiniband/hw/nes/nes_cm.c
@@ -854,9 +854,8 @@ static struct nes_cm_listener *find_list
{
unsigned long flags;
struct nes_cm_listener *listen_node;
-#ifdef CONFIG_INFINIBAND_NES_DEBUG
- __be32 tmp_addr = cpu_to_be32(dst_addr);
-#endif
+ __be32 uninitialized_var(tmp_addr) = cpu_to_be32(dst_addr);
+
/* walk list and find cm_node associated with this session ID */
spin_lock_irqsave(&cm_core->listen_list_lock, flags);
list_for_each_entry(listen_node, &cm_core->listen_list.list, list) {


but that seems a bit abusive ;)

2009-04-16 01:12:45

by helight.xu

[permalink] [raw]
Subject: Re: [PATCH] fix a warning on drivers/infiniband/hw/nes/nes_cm.c:862:

On Wed, Apr 15, 2009 at 02:32:28PM -0700, Andrew Morton wrote:
> On Sun, 12 Apr 2009 20:23:17 +0800
> Zhenwen Xu <[email protected]> wrote:
>
> > Fix this warning:
> > drivers/infiniband/hw/nes/nes_cm.c:862: warning: unused variable ___tmp_addr___
> >
> > the 'tmp_addr' is defined for debug, so it should be defined in
> > CONFIG_INFINIBAND_NES_DEBUG
> >
> >
> > >From 5f67884bcda5450807dcd080378d829628e4db1c Mon Sep 17 00:00:00 2001
> > From: Zhenwen Xu <[email protected]>
> > Date: Sun, 12 Apr 2009 20:12:18 +0800
> > Subject: [PATCH] fix a warning on drivers/infiniband/hw/nes/nes_cm.c:862:
> >
> > Signed-off-by: Zhenwen Xu <[email protected]>
> > ---
> > drivers/infiniband/hw/nes/nes_cm.c | 3 ++-
> > 1 files changed, 2 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/infiniband/hw/nes/nes_cm.c b/drivers/infiniband/hw/nes/nes_cm.c
> > index dbd9a75..1bad93b 100644
> > --- a/drivers/infiniband/hw/nes/nes_cm.c
> > +++ b/drivers/infiniband/hw/nes/nes_cm.c
> > @@ -854,8 +854,9 @@ static struct nes_cm_listener *find_listener(struct nes_cm_core *cm_core,
> > {
> > unsigned long flags;
> > struct nes_cm_listener *listen_node;
> > +#ifdef CONFIG_INFINIBAND_NES_DEBUG
> > __be32 tmp_addr = cpu_to_be32(dst_addr);
> > -
> > +#endif
> > /* walk list and find cm_node associated with this session ID */
> > spin_lock_irqsave(&cm_core->listen_list_lock, flags);
> > list_for_each_entry(listen_node, &cm_core->listen_list.list, list) {
>
> eek, an ugly ifdef. And we can't just remove tmp_addr because
> printk(%p) wants to be passed an address rather than a value.
>
> It'd be nice if we had a handy macro to squish the warning, like
> uninitialized_var.
>
> As it happens, uninitialized_var() _does_ suppress the unused-var warning:
>
> --- a/drivers/infiniband/hw/nes/nes_cm.c~drivers-infiniband-hw-nes-nes_cmc-fix-unused-var-warning-cleanup
> +++ a/drivers/infiniband/hw/nes/nes_cm.c
> @@ -854,9 +854,8 @@ static struct nes_cm_listener *find_list
> {
> unsigned long flags;
> struct nes_cm_listener *listen_node;
> -#ifdef CONFIG_INFINIBAND_NES_DEBUG
> - __be32 tmp_addr = cpu_to_be32(dst_addr);
> -#endif
> + __be32 uninitialized_var(tmp_addr) = cpu_to_be32(dst_addr);
> +
> /* walk list and find cm_node associated with this session ID */
> spin_lock_irqsave(&cm_core->listen_list_lock, flags);
> list_for_each_entry(listen_node, &cm_core->listen_list.list, list) {
>
>
> but that seems a bit abusive ;)
Thanks! I got.

--
---------------------------------
Zhenwen Xu - Open and Free
Home Page: http://zhwen.org
My Studio: http://dim4.cn