diff mbox series

media: ov9650: avoid maybe-uninitialized warnings

Message ID 20180926125127.2004280-1-arnd@arndb.de
State Accepted
Commit 146c45ef1fec3e3217b78c5a606efe41150301ea
Headers show
Series media: ov9650: avoid maybe-uninitialized warnings | expand

Commit Message

Arnd Bergmann Sept. 26, 2018, 12:51 p.m. UTC
The regmap change causes multiple warnings like

drivers/media/i2c/ov9650.c: In function 'ov965x_g_volatile_ctrl':
drivers/media/i2c/ov9650.c:889:29: error: 'reg2' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   exposure = ((reg2 & 0x3f) << 10) | (reg1 << 2) |
              ~~~~~~~~~~~~~~~^~~~~~

It is apparently hard for the compiler to see here if ov965x_read()
returned successfully or not. Besides, we have a v4l2_dbg() statement
that prints an uninitialized value if regmap_read() fails.

Adding an 'else' clause avoids the ambiguity.

Fixes: 361f3803adfe ("media: ov9650: use SCCB regmap")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
 drivers/media/i2c/ov9650.c | 2 ++
 1 file changed, 2 insertions(+)

-- 
2.18.0

Comments

Sakari Ailus Sept. 26, 2018, 9:17 p.m. UTC | #1
Hi Arnd,

On Wed, Sep 26, 2018 at 02:51:01PM +0200, Arnd Bergmann wrote:
> The regmap change causes multiple warnings like

> 

> drivers/media/i2c/ov9650.c: In function 'ov965x_g_volatile_ctrl':

> drivers/media/i2c/ov9650.c:889:29: error: 'reg2' may be used uninitialized in this function [-Werror=maybe-uninitialized]

>    exposure = ((reg2 & 0x3f) << 10) | (reg1 << 2) |

>               ~~~~~~~~~~~~~~~^~~~~~

> 

> It is apparently hard for the compiler to see here if ov965x_read()

> returned successfully or not. Besides, we have a v4l2_dbg() statement

> that prints an uninitialized value if regmap_read() fails.

> 

> Adding an 'else' clause avoids the ambiguity.


Thanks!

I'm not sure what happened here but the two lines use spaces for
indentation. I've replaced those with tabs.

> 

> Fixes: 361f3803adfe ("media: ov9650: use SCCB regmap")

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> ---

>  drivers/media/i2c/ov9650.c | 2 ++

>  1 file changed, 2 insertions(+)

> 

> diff --git a/drivers/media/i2c/ov9650.c b/drivers/media/i2c/ov9650.c

> index 3c9e6798d14b..77944da31de1 100644

> --- a/drivers/media/i2c/ov9650.c

> +++ b/drivers/media/i2c/ov9650.c

> @@ -433,6 +433,8 @@ static int ov965x_read(struct ov965x *ov965x, u8 addr, u8 *val)

>  	ret = regmap_read(ov965x->regmap, addr, &buf);

>  	if (!ret)

>  		*val = buf;

> +        else

> +                *val = -1;

>  

>  	v4l2_dbg(2, debug, &ov965x->sd, "%s: 0x%02x @ 0x%02x. (%d)\n",

>  		 __func__, *val, addr, ret);


-- 
Kind regards,

Sakari Ailus
sakari.ailus@linux.intel.com
diff mbox series

Patch

diff --git a/drivers/media/i2c/ov9650.c b/drivers/media/i2c/ov9650.c
index 3c9e6798d14b..77944da31de1 100644
--- a/drivers/media/i2c/ov9650.c
+++ b/drivers/media/i2c/ov9650.c
@@ -433,6 +433,8 @@  static int ov965x_read(struct ov965x *ov965x, u8 addr, u8 *val)
 	ret = regmap_read(ov965x->regmap, addr, &buf);
 	if (!ret)
 		*val = buf;
+        else
+                *val = -1;
 
 	v4l2_dbg(2, debug, &ov965x->sd, "%s: 0x%02x @ 0x%02x. (%d)\n",
 		 __func__, *val, addr, ret);