Re: [PATCH] rio: warn_unused_result warnings fix

[Li Yang <leoli@freescale.com>]

On Tue, Apr 28, 2009 at 6:51 PM, Michael Ellerman
<michael@ellerman.id.au> wrote:
> On Tue, 2009-04-28 at 18:15 +0800, Li Yang wrote:
>> warning: ignoring return value of 'device_add', declared with attribute =
warn_unused_result
>> warning: ignoring return value of 'sysfs_create_bin_file', declared with=
 attribute warn_unused_result
>>
>> Signed-off-by: Li Yang <leoli@freescale.com>
>> ---
>> =C2=A0drivers/rapidio/rio-scan.c =C2=A0| =C2=A0 =C2=A05 ++++-
>> =C2=A0drivers/rapidio/rio-sysfs.c | =C2=A0 =C2=A06 ++++--
>> =C2=A02 files changed, 8 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/rapidio/rio-scan.c b/drivers/rapidio/rio-scan.c
>> index 74d0bfa..9309e24 100644
>> --- a/drivers/rapidio/rio-scan.c
>> +++ b/drivers/rapidio/rio-scan.c
>> @@ -265,7 +265,10 @@ static void rio_route_set_ops(struct rio_dev *rdev)
>> =C2=A0 */
>> =C2=A0static void __devinit rio_add_device(struct rio_dev *rdev)
>> =C2=A0{
>> - =C2=A0 =C2=A0 device_add(&rdev->dev);
>> + =C2=A0 =C2=A0 int err;
>> +
>> + =C2=A0 =C2=A0 err =3D device_add(&rdev->dev);
>> + =C2=A0 =C2=A0 WARN_ON(err);
>>
>> =C2=A0 =C2=A0 =C2=A0 spin_lock(&rio_global_list_lock);
>> =C2=A0 =C2=A0 =C2=A0 list_add_tail(&rdev->global_list, &rio_devices);
>
> Is that really useful? Why not return the error to rio_setup_device()
> which can tell it's caller.

IMHO, when device_add() fails the system is quite broken.  So the
value is very limited for it to fail cleanly, which need some effort
to implement.  I can add it if you insist.

- Leo