[U-Boot] [PATCH 02/10] USB add macros for debugging usb device setup.

Tom Tom.Rix at windriver.com
Sun Nov 1 15:02:22 CET 2009


Mike Frysinger wrote:
> On Saturday 31 October 2009 22:00:09 Tom wrote:
>> Mike Frysinger wrote:
>>> On Saturday 31 October 2009 13:37:39 Tom Rix wrote:
>>>> +#ifdef DEBUG
>>>> +static inline void print_device_descriptor(struct usb_device_descriptor
>>>>  *d) +{
>>>> +	serial_printf("usb device descriptor \n");
>>> do you really need serial_printf() ?  what's wrong with debug() ?  then
>>> you dont even really need "#ifdef DEBUG" around all the functions ...
>> The explicit serial_printf is done because this patch set changes the
>> stdin and stdout for serial to usbtty.
>>
>> When you use printf to debug printf, you regress into a bad state.
> 
> so in your specific use case it makes sense *some* of the time (usbtty is 
> enabled and the console has been changed to it), but in the general use case 
> (usb debugging), it does not.  why not make it intelligent instead of 
> penalizing everyone to use their serial console:
>  - default to debug()
>  - if usbtty support is enabled, check the current stdout console to see if 
> it's set to a usbtty, and only then fall back to forcing serial_printf()
> -mike

A better solution would be to combine this logic into debug().

Tom


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