[PATCH 1/2] drm/ttm: add a way to bo_wait for either the last read or last write

[Thomas Hellstrom]

On 10/08/2011 01:27 PM, Ville Syrjälä wrote:
> On Sat, Oct 08, 2011 at 01:10:13PM +0200, Thomas Hellstrom wrote:
>    
>> On 10/08/2011 12:26 PM, Ville Syrjälä wrote:
>>      
>>> On Fri, Oct 07, 2011 at 10:58:13AM +0200, Thomas Hellstrom wrote:
>>>
>>>        
>>>> Oh, and one more style comment below:
>>>>
>>>> On 08/07/2011 10:39 PM, Marek Olšák wrote:
>>>>
>>>>          
>>>>> +enum ttm_buffer_usage {
>>>>> +    TTM_USAGE_READ = 1,
>>>>> +    TTM_USAGE_WRITE = 2,
>>>>> +    TTM_USAGE_READWRITE = TTM_USAGE_READ | TTM_USAGE_WRITE
>>>>> +};
>>>>>
>>>>>
>>>>>
>>>>>            
>>>> Please don't use enums for bit operations.
>>>>
>>>>          
>>> Now I'm curious. Why not?
>>>
>>>
>>>        
>> Because it's inconsistent with how flags are defined in the rest of the
>> TTM module.
>>      
> Ah OK. I was wondering if there's some subtle technical issue involved.
> I've recently gotten to the habit of using enums for pretty much all
> constants. Just easier on the eye IMHO, and avoids cpp output from
> looking like number soup.
>
>    

Yes, there are a number of advantages, including symbolic debugger output.
If we had flag enums that enumerated 1, 2, 4, 8 etc. I'd feel motivated 
to move
all TTM definitions over.

/Thomas