Re: [PATCH] platform: x86: hp_wireless: Inform the user if hp_wireless_input_setup()/add() fails

[Alex Hung]

Hi,

I think adding a pr_err message has a benefit - if kernel prints this
message, a develop can quickly identify where it gets wrong by a
string search on entire kernel source code.

Other than this, both solutions are great.



On Sat, Nov 29, 2014 at 8:04 AM, Borislav Petkov <bp@xxxxxxxxx> wrote:
> On Sat, Nov 29, 2014 at 01:48:31AM +0200, Giedrius Statkevicius wrote:
>> On 2014.11.29 01:15, Borislav Petkov wrote:
>> > On Sat, Nov 29, 2014 at 12:14:27AM +0200, Giedrius Statkevicius wrote:
>> >> In hpwl_add() there is a unused variable err to which we assign the
>> >> result of hp_wireless_input_setup() but we don't do anything depending
>> >> on the result so print out a message that informs the user if add()
>> >> (hp_wireless_input_setup()) fails since acpi_device_probe() doesn't
>> >> print anything in this case.
>> >>
>> >> Signed-off-by: Giedrius Statkevicius <giedriuswork@xxxxxxxxx>
>> >> ---
>> >>  drivers/platform/x86/hp-wireless.c | 3 +++
>> >>  1 file changed, 3 insertions(+)
>> >>
>> >> diff --git a/drivers/platform/x86/hp-wireless.c b/drivers/platform/x86/hp-wireless.c
>> >> index 415348f..4e4cc8b 100644
>> >> --- a/drivers/platform/x86/hp-wireless.c
>> >> +++ b/drivers/platform/x86/hp-wireless.c
>> >> @@ -85,6 +85,9 @@ static int hpwl_add(struct acpi_device *device)
>> >>    int err;
>> >>
>> >>    err = hp_wireless_input_setup();
>> >> +  if (err)
>> >> +          pr_err("Failed to setup hp wireless hotkeys\n");
>> >> +
>> >
>> > I don't think there's need for that. Just do:
>> >
>> >     return hp_wireless_input_setup();
>> >
>> > and drop err completely.
>> >
>> > The upper layer which calls the ->add() method should propagate the
>> > error properly.
>> Looking at other platform drivers code some add() methods do give
>> information to the user via pr_{err,warn,info} macros, some don't. My
>> first patch to deal with this just removed the err variable like you
>> have wrote but Darren Hart and Rafael J. Wysocki commented that maybe it
>> should be better to inform the user about this error. That is why
>> probably there was a variable for this in the first place but probably
>> the original author just forgot to add a pr_err().
>
> Ah, I see. Original author added to CC.
>
> --
> Regards/Gruss,
>     Boris.
>
> Sent from a fat crate under my desk. Formatting is fine.
> --



-- 
Cheers,
Alex Hung
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