Re: FAQ Somewhere? USB error messges

[Randy Dunlap <randy.dunlap@oracle.com>]

Yan Seiner wrote:
> Greg KH wrote:
>> On Wed, Feb 18, 2009 at 07:13:24PM -0800, Yan Seiner wrote:
>>  
>>> I have a device that has fallen off my usb hub.  It now refuses to
>>> connect with:
>>>
>>> Feb 18 18:57:21 selene kernel: [217569.165436] usb 2-4.4.4.4.4.3: new
>>> low speed USB device using ehci_hcd and address 55
>>> Feb 18 18:57:22 selene kernel: [217569.572035] usb 2-4.4.4.4.4.3:
>>> device not accepting address 55, error -71
>>> Feb 18 18:57:22 selene kernel: [217569.572366] hub 2-4.4.4.4.4:1.0:
>>> unable to enumerate USB device on port 3
>>>
>>> I'm fairly sure it's not the device as I have two identical ones that
>>> work fine in other hubs.  I'm fairly sure it's not the hub as I have
>>> other devices that work fine on that hub.
>>>
>>> So now I need to figure out what that error message means.  Where can
>>> I look up the error code?
>>>     
>>
>> Documentation/usb/error-codes.txt
>>
>>   
> That says things like:
> 
> -ENODEV         specified USB-device or bus doesn't exist
> 
> -ENOENT         specified interface or endpoint does not exist or
>                is not enabled
> 
> 
> It has no information on translating 71 to E*.  Unfortunately that
> doesn't tell me what 71 is about. Grepping /usr/include for some of
> those errors *still* doesn't tell me what error 71 is as it doesn't
> appear anywhere.

$ grep -w 71 /usr/include/asm-generic/errno.h
#define	EPROTO		71	/* Protocol error */

and see EPROTO in the file that Greg referred you to.

> Is there any reason why the hotplug subsystem has to throw those cryptic
> errors with no pointers to any docs where we might be able to decipher
> them?  We're in userland; we don't deal with this on a daily basis, and
> we have no clue where any of the info we need to understand those errors
> lies.


-- 
~Randy