Re: [PATCH] driver core: show the error number when driver_sysfs_add() fails

[Kefeng Wang]

On 2019/6/4 13:33, Greg Kroah-Hartman wrote:
> On Tue, Jun 04, 2019 at 12:15:46PM +0800, Kefeng Wang wrote:
>> If driver_sysfs_add() fails, kernel shows following message,
>>
>>   really_probe: driver_sysfs_add(portman.0) failed
>>   ppdev: probe of portman.0 failed with error 0
>>
>> It's better to show the error number like other probe_failed path.
>>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
>> ---
>>  drivers/base/dd.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
>> index 0df9b4461766..04ee4e196530 100644
>> --- a/drivers/base/dd.c
>> +++ b/drivers/base/dd.c
>> @@ -493,7 +493,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>>  			goto probe_failed;
>>  	}
>>  
>> -	if (driver_sysfs_add(dev)) {
>> +	ret = driver_sysfs_add(dev);
>> +	if (ret) {
>>  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
>>  			__func__, dev_name(dev));
> Shouldn't this be where the error number is shown?  No need for all
> callers to also show the same thing.

Like the message shown as above, there is a common path to show all the probe error info,

"ppdev: probe of portman.0 failed with error 0"

but the driver_sysfs_add() error handling won't fill with ret, so error '0' is shown.
after this patch,

 really_probe: driver_sysfs_add(portman.0) failed
 ppdev: probe of portman.0 failed with error -12

>
> thanks,
>
> greg k-h
>
> .
>