(In reply to comment #1) > RGTC1 texturing uses only 4 bits of precision in R500, which can cause some > piglit failures. If you run the test, you'll see how the precision affects > the filtered texture. If it's not completely wrong, let's just say this is a > hardware limitation. Yeah, the pictures before and after patch looks almost similar, so probably indeed a precision bug, dunno why it passed before though.