* [PATCH][next] can: kvaser_pciefd: remove redundant negative check on trigger
@ 2019-07-25 11:25 Colin King
2019-07-25 12:37 ` walter harms
0 siblings, 1 reply; 3+ messages in thread
From: Colin King @ 2019-07-25 11:25 UTC (permalink / raw)
To: Wolfgang Grandegger, Marc Kleine-Budde, David S . Miller,
linux-can, netdev
Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
The check to see if trigger is less than zero is always false, trigger
is always in the range 0..255. Hence the check is redundant and can
be removed.
Addresses-Coverity: ("Logically dead code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
drivers/net/can/kvaser_pciefd.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c
index 3af747cbbde4..68e00aad0810 100644
--- a/drivers/net/can/kvaser_pciefd.c
+++ b/drivers/net/can/kvaser_pciefd.c
@@ -652,9 +652,6 @@ static void kvaser_pciefd_pwm_stop(struct kvaser_pciefd_can *can)
top = (pwm_ctrl >> KVASER_PCIEFD_KCAN_PWM_TOP_SHIFT) & 0xff;
trigger = (100 * top + 50) / 100;
- if (trigger < 0)
- trigger = 0;
-
pwm_ctrl = trigger & 0xff;
pwm_ctrl |= (top & 0xff) << KVASER_PCIEFD_KCAN_PWM_TOP_SHIFT;
iowrite32(pwm_ctrl, can->reg_base + KVASER_PCIEFD_KCAN_PWM_REG);
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH][next] can: kvaser_pciefd: remove redundant negative check on trigger
2019-07-25 11:25 [PATCH][next] can: kvaser_pciefd: remove redundant negative check on trigger Colin King
@ 2019-07-25 12:37 ` walter harms
2019-07-25 12:41 ` Colin Ian King
0 siblings, 1 reply; 3+ messages in thread
From: walter harms @ 2019-07-25 12:37 UTC (permalink / raw)
To: Colin King
Cc: Wolfgang Grandegger, Marc Kleine-Budde, David S . Miller,
linux-can, netdev, kernel-janitors, linux-kernel
Am 25.07.2019 13:25, schrieb Colin King:
> From: Colin Ian King <colin.king@canonical.com>
>
> The check to see if trigger is less than zero is always false, trigger
> is always in the range 0..255. Hence the check is redundant and can
> be removed.
>
> Addresses-Coverity: ("Logically dead code")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> drivers/net/can/kvaser_pciefd.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c
> index 3af747cbbde4..68e00aad0810 100644
> --- a/drivers/net/can/kvaser_pciefd.c
> +++ b/drivers/net/can/kvaser_pciefd.c
> @@ -652,9 +652,6 @@ static void kvaser_pciefd_pwm_stop(struct kvaser_pciefd_can *can)
> top = (pwm_ctrl >> KVASER_PCIEFD_KCAN_PWM_TOP_SHIFT) & 0xff;
>
> trigger = (100 * top + 50) / 100;
> - if (trigger < 0)
> - trigger = 0;
> -
to be fair i do not understand the calculation here here.
(100*top+50)/100 = top+50/100
but seems to be int so it should be =top
did i missunderstand something here ?
re,
wh
> pwm_ctrl = trigger & 0xff;
> pwm_ctrl |= (top & 0xff) << KVASER_PCIEFD_KCAN_PWM_TOP_SHIFT;
> iowrite32(pwm_ctrl, can->reg_base + KVASER_PCIEFD_KCAN_PWM_REG);
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH][next] can: kvaser_pciefd: remove redundant negative check on trigger
2019-07-25 12:37 ` walter harms
@ 2019-07-25 12:41 ` Colin Ian King
0 siblings, 0 replies; 3+ messages in thread
From: Colin Ian King @ 2019-07-25 12:41 UTC (permalink / raw)
To: wharms
Cc: Wolfgang Grandegger, Marc Kleine-Budde, David S . Miller,
linux-can, netdev, kernel-janitors, linux-kernel
On 25/07/2019 13:37, walter harms wrote:
>
>
> Am 25.07.2019 13:25, schrieb Colin King:
>> From: Colin Ian King <colin.king@canonical.com>
>>
>> The check to see if trigger is less than zero is always false, trigger
>> is always in the range 0..255. Hence the check is redundant and can
>> be removed.
>>
>> Addresses-Coverity: ("Logically dead code")
>> Signed-off-by: Colin Ian King <colin.king@canonical.com>
>> ---
>> drivers/net/can/kvaser_pciefd.c | 3 ---
>> 1 file changed, 3 deletions(-)
>>
>> diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c
>> index 3af747cbbde4..68e00aad0810 100644
>> --- a/drivers/net/can/kvaser_pciefd.c
>> +++ b/drivers/net/can/kvaser_pciefd.c
>> @@ -652,9 +652,6 @@ static void kvaser_pciefd_pwm_stop(struct kvaser_pciefd_can *can)
>> top = (pwm_ctrl >> KVASER_PCIEFD_KCAN_PWM_TOP_SHIFT) & 0xff;
>>
>> trigger = (100 * top + 50) / 100;
>> - if (trigger < 0)
>> - trigger = 0;
>> -
> to be fair i do not understand the calculation here here.
> (100*top+50)/100 = top+50/100
>
> but seems to be int so it should be =top
Indeed it does not do anything, that does look like an unintentional
bug. Good catch.
>
> did i missunderstand something here ?
>
> re,
> wh
>
>
>> pwm_ctrl = trigger & 0xff;
>> pwm_ctrl |= (top & 0xff) << KVASER_PCIEFD_KCAN_PWM_TOP_SHIFT;
>> iowrite32(pwm_ctrl, can->reg_base + KVASER_PCIEFD_KCAN_PWM_REG);
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-07-25 12:41 UTC | newest]
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