https://bugs.freedesktop.org/show_bug.cgi?id=75061

--- Comment #12 from Marek Olšák maraeo@gmail.com --- All writes to valid_buffer_range are protected by a mutex. Only the reads are not.

I've got no idea what to do with invalidate_buffer. If we added mutexes everywhere, it would slow down the driver.

I think that calling BufferData in one thread and using the buffer for rendering in some other thread is a race condition in the application and should be fixed in the app.