2024-02-05 18:04:51

by Colin Ian King

Subject: [PATCH][next] comedi: remove redundant assignment to variable range

The variable range is being initialized with a value that is never
read, it is being re-assigned later on. The initialization is
redundant and can be removed.

Cleans up clang scan build warning:
drivers/comedi/drivers/das08.c:180:2: warning: Value stored
to 'range' is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <[email protected]>
---
drivers/comedi/drivers/das08.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/comedi/drivers/das08.c b/drivers/comedi/drivers/das08.c
index 5d5b9174f88a..49944ce1f813 100644
--- a/drivers/comedi/drivers/das08.c
+++ b/drivers/comedi/drivers/das08.c
@@ -177,7 +177,6 @@ static int das08_ai_insn_read(struct comedi_device *dev,
int ret;

chan = CR_CHAN(insn->chanspec);
- range = CR_RANGE(insn->chanspec);

/* clear crap */
inb(dev->iobase + DAS08_AI_LSB_REG);
--
2.39.2

2024-02-06 12:33:46

by Ian Abbott

Subject: Re: [PATCH][next] comedi: remove redundant assignment to variable range

On 05/02/2024 18:04, Colin Ian King wrote:
> The variable range is being initialized with a value that is never
> read, it is being re-assigned later on. The initialization is
> redundant and can be removed.
>
> Cleans up clang scan build warning:
> drivers/comedi/drivers/das08.c:180:2: warning: Value stored
> to 'range' is never read [deadcode.DeadStores]
>
> Signed-off-by: Colin Ian King <[email protected]>
> ---
> drivers/comedi/drivers/das08.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/comedi/drivers/das08.c b/drivers/comedi/drivers/das08.c
> index 5d5b9174f88a..49944ce1f813 100644
> --- a/drivers/comedi/drivers/das08.c
> +++ b/drivers/comedi/drivers/das08.c
> @@ -177,7 +177,6 @@ static int das08_ai_insn_read(struct comedi_device *dev,
> int ret;
>
> chan = CR_CHAN(insn->chanspec);
> - range = CR_RANGE(insn->chanspec);
>
> /* clear crap */
> inb(dev->iobase + DAS08_AI_LSB_REG);

Thanks. It looks like it gets reassigned to the same value further
down, closer to the point where the value is used (within an `if`
block), and so it doesn't matter which of the assignments is removed.

Reviewed-by: Ian Abbott <[email protected]>

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