Re: [PATCH v3 2/2] misc: pvpanic: introduce module parameter 'events'

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Jan 08, 2021 at 09:52:23PM +0800, zhenwei pi wrote:
> Suggested by Paolo, add a module parameter that can be used to limit
> which capabilities the driver uses.
> 
> Finally, the pvpanic guest driver works by the limitation of both
> device capability and user setting.
> 
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
>  drivers/misc/pvpanic.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/pvpanic.c b/drivers/misc/pvpanic.c
> index e1023c7b8fb0..417f1086e764 100644
> --- a/drivers/misc/pvpanic.c
> +++ b/drivers/misc/pvpanic.c
> @@ -19,6 +19,10 @@
>  #include <uapi/misc/pvpanic.h>
>  
>  static void __iomem *base;
> +static unsigned int events = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
> +module_param(events, uint, 0644);
> +MODULE_PARM_DESC(events, "set event limitation of pvpanic device");

I do not understand you wanting a module parameter as well as a sysfs
file.  Why is this needed?  Why are you spreading this information out
across different apis and locations?

Again, adding module parameters is almost never a good idea anymore,
they are a pain to manage and use.

thanks,

greg k-h