https://bugs.freedesktop.org/show_bug.cgi?id=70327
--- Comment #10 from Vadim Girlin ptpzz@yandex.ru --- Created attachment 87364 --> https://bugs.freedesktop.org/attachment.cgi?id=87364&action=edit patch
This patch should fix the issue (only compile-tested so far, I can't test with r600g card right now, but hopefully it's simple enough to be correct).