Radeon wait idle

[Thomas H. <th...@sh...>]

Jerome and other Radeon developers.

You're probably aware of this, but I'd thought I'd mention it before the 
Radeon user-space interface is set in stone.

There is a slight problem with the radeon bo wait idle ioctl if there 
are multiple threads or processes rendering to the same buffer without 
synchronization.
The ioctl effectively guarantees that all graphics commands put in the 
pipeline before the ioctl was called are finished, but it can never 
guarantee that the buffer is idle on return.

I'm not sure this is a problem in practice, though.

/Thomas