Re: [PATCH] drivers: pnp: proc.c: Removed unnecessary varibles

[Shuah Khan <skhan@linuxfoundation.org>]

On 4/22/21 12:03 PM, Anupama K Patil wrote:
> de, e are two variables of the type 'struct proc_dir_entry'
> which can be removed to save memory. This also fixes a coding style
> issue reported by checkpatch where we are suggested to make assignment
> outside the if statement.
> 

Sounds like a reasonable change.

> Signed-off-by: Anupama K Patil <anupamakpatil123@gmail.com>
> ---
>   drivers/pnp/isapnp/proc.c | 13 ++++++-------
>   1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/pnp/isapnp/proc.c b/drivers/pnp/isapnp/proc.c
> index 785a796430fa..1ae458c02656 100644
> --- a/drivers/pnp/isapnp/proc.c
> +++ b/drivers/pnp/isapnp/proc.c
> @@ -57,21 +57,20 @@ static const struct proc_ops isapnp_proc_bus_proc_ops = {
>   static int isapnp_proc_attach_device(struct pnp_dev *dev)
>   {
>   	struct pnp_card *bus = dev->card;
> -	struct proc_dir_entry *de, *e;
>   	char name[16];
>   
> -	if (!(de = bus->procdir)) {
> +	if (!bus->procdir) {
>   		sprintf(name, "%02x", bus->number);

It would make sense to change this to scnprintf()

> -		de = bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
> -		if (!de)
> +		bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
> +		if (!bus->procdir)
>   			return -ENOMEM;
>   	}
>   	sprintf(name, "%02x", dev->number);

It would make sense to change this to scnprintf()

> -	e = dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, de,
> +	dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, bus->procdir,
>   					    &isapnp_proc_bus_proc_ops, dev);
> -	if (!e)
> +	if (!dev->procent)
>   		return -ENOMEM;

Shouldn't the procdir be deleted when proc_create_data() fails?

> -	proc_set_size(e, 256);
> +	proc_set_size(dev->procent, 256);
>   	return 0;
>   }
>   
> 

Note that isapnp_proc_init() doesn't check isapnp_proc_attach_device()
return and handle errors and cleanup.

thanks,
-- Shuah