diff mbox series

media: mantis: remove redundant assignment to variable err

Message ID 20200410113913.14430-1-colin.king@canonical.com (mailing list archive)
State New, archived
Headers show
Series media: mantis: remove redundant assignment to variable err | expand

Commit Message

Colin King April 10, 2020, 11:39 a.m. UTC
From: Colin Ian King <colin.king@canonical.com>

The variable err is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/media/pci/mantis/hopper_vp3028.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Ezequiel Garcia April 11, 2020, 10:53 p.m. UTC | #1
Hi Colin,

Thanks for your patch!

On Fri, 10 Apr 2020 at 08:39, Colin King <colin.king@canonical.com> wrote:
>
> From: Colin Ian King <colin.king@canonical.com>
>
> The variable err is being initialized with a value that is never read
> and it is being updated later with a new value.  The initialization is
> redundant and can be removed.
>
> Addresses-Coverity: ("Unused value")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/media/pci/mantis/hopper_vp3028.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/pci/mantis/hopper_vp3028.c b/drivers/media/pci/mantis/hopper_vp3028.c
> index 37bd386f3ed8..ce1e8737b14b 100644
> --- a/drivers/media/pci/mantis/hopper_vp3028.c
> +++ b/drivers/media/pci/mantis/hopper_vp3028.c
> @@ -33,7 +33,7 @@ static int vp3028_frontend_init(struct mantis_pci *mantis, struct dvb_frontend *
>  {
>         struct i2c_adapter *adapter     = &mantis->adapter;
>         struct mantis_hwconfig *config  = mantis->hwconfig;
> -       int err = 0;
> +       int err;
>
>         mantis_gpio_set_bits(mantis, config->reset, 0);
>         msleep(100);

There's a redundant err assignment right below here,
which you can also get rid of:

-       err = mantis_frontend_power(mantis, POWER_ON);
+       mantis_frontend_power(mantis, POWER_ON);

I can't test this, but calling mantis_frontend_power twice
is possibly redundant.

Also, what's the gain from this cleanup? The driver is super
old, and it seems any modern compiler would be oblivious
of the redundant assignment.

Thanks!
Ezequiel
Dan Carpenter April 14, 2020, 8:59 a.m. UTC | #2
On Sat, Apr 11, 2020 at 07:53:51PM -0300, Ezequiel Garcia wrote:
> There's a redundant err assignment right below here,
> which you can also get rid of:
> 
> -       err = mantis_frontend_power(mantis, POWER_ON);
> +       mantis_frontend_power(mantis, POWER_ON);
> 
> I can't test this, but calling mantis_frontend_power twice
> is possibly redundant.

To me that code really looks like a hack-around for flakey hardware and
I would be afraid to delete it.  But the "err =" could be removed.

> 
> Also, what's the gain from this cleanup? The driver is super
> old, and it seems any modern compiler would be oblivious
> of the redundant assignment.

Eventually we would like to enable that warning by default but there are
still thousands of pointless assignments so it will take years of
small fixes like this.  Generally cleaning up warnings is good.

regards,
dan carpenter
Colin King April 14, 2020, 9:11 a.m. UTC | #3
On 14/04/2020 09:59, Dan Carpenter wrote:
> On Sat, Apr 11, 2020 at 07:53:51PM -0300, Ezequiel Garcia wrote:
>> There's a redundant err assignment right below here,
>> which you can also get rid of:
>>
>> -       err = mantis_frontend_power(mantis, POWER_ON);
>> +       mantis_frontend_power(mantis, POWER_ON);
>>
>> I can't test this, but calling mantis_frontend_power twice
>> is possibly redundant.
> 
> To me that code really looks like a hack-around for flakey hardware and
> I would be afraid to delete it.  But the "err =" could be removed.
> 
>>
>> Also, what's the gain from this cleanup? The driver is super
>> old, and it seems any modern compiler would be oblivious
>> of the redundant assignment.
> 
> Eventually we would like to enable that warning by default but there are
> still thousands of pointless assignments so it will take years of
> small fixes like this.  Generally cleaning up warnings is good.

They are indeed trivial fixes but can allow us to later find real
unassigned variable bugs in the future when new code gets added and does
not set these variables.

Colin
> 
> regards,
> dan carpenter
>
diff mbox series

Patch

diff --git a/drivers/media/pci/mantis/hopper_vp3028.c b/drivers/media/pci/mantis/hopper_vp3028.c
index 37bd386f3ed8..ce1e8737b14b 100644
--- a/drivers/media/pci/mantis/hopper_vp3028.c
+++ b/drivers/media/pci/mantis/hopper_vp3028.c
@@ -33,7 +33,7 @@  static int vp3028_frontend_init(struct mantis_pci *mantis, struct dvb_frontend *
 {
 	struct i2c_adapter *adapter	= &mantis->adapter;
 	struct mantis_hwconfig *config	= mantis->hwconfig;
-	int err = 0;
+	int err;
 
 	mantis_gpio_set_bits(mantis, config->reset, 0);
 	msleep(100);