Re: [PATCH v3 12/14] intel_gna: add a 'misc' device

[Greg Kroah-Hartman]

On Thu, May 13, 2021 at 01:00:38PM +0200, Maciej Kwapulinski wrote:
> The new 'misc' device is the node for applications in user space to
> interact with the driver.
> 
> Signed-off-by: Maciej Kwapulinski <maciej.kwapulinski@xxxxxxxxxxxxxxx>
> Tested-by: Savo Novakovic <savox.novakovic@xxxxxxxxx>
> ---
>  drivers/misc/intel/gna/device.c | 52 +++++++++++++++++++++++++++++++--
>  drivers/misc/intel/gna/device.h | 11 +++----
>  2 files changed, 55 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/misc/intel/gna/device.c b/drivers/misc/intel/gna/device.c
> index 0e31b8c6bb70..1e6345a8325b 100644
> --- a/drivers/misc/intel/gna/device.c
> +++ b/drivers/misc/intel/gna/device.c
> @@ -20,6 +20,18 @@ module_param(recovery_timeout, int, 0644);
>  MODULE_PARM_DESC(recovery_timeout, "Recovery timeout in seconds");
>  #endif
>  
> +struct file;
> +
> +static int gna_open(struct inode *inode, struct file *f)
> +{
> +	return -EPERM;
> +}

That sucks, why have an open that does nothing but fail?

> +
> +static const struct file_operations gna_file_ops = {
> +	.owner		=	THIS_MODULE,
> +	.open		=	gna_open,
> +};
> +
>  static void gna_devm_idr_destroy(void *data)
>  {
>  	struct idr *idr = data;
> @@ -27,6 +39,36 @@ static void gna_devm_idr_destroy(void *data)
>  	idr_destroy(idr);
>  }
>  
> +static void gna_devm_deregister_misc_dev(void *data)

Why is this a void *?

This isn't windows, use real pointer types everywhere in the kernel
please.

> +{
> +	struct miscdevice *misc = data;
> +
> +	misc_deregister(misc);
> +}
> +
> +static int gna_devm_register_misc_dev(struct device *parent, struct miscdevice *misc)
> +{
> +	int ret;
> +
> +	ret = misc_register(misc);
> +	if (ret) {
> +		dev_err(parent, "misc device %s registering failed. errcode: %d\n",
> +			misc->name, ret);
> +		gna_devm_deregister_misc_dev(misc);
> +	} else {
> +		dev_dbg(parent, "device: %s registered\n",
> +			misc->name);

You have loads of debugging in this driver still, is it really needed?

> +	}
> +
> +	ret = devm_add_action(parent, gna_devm_deregister_misc_dev, misc);

Why do you need this?


thanks,

greg k-h