From 167ffc44caaee68ea60dadf6931a4d195a4ed1f0 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Sat, 17 Jul 2010 12:28:02 +0200 Subject: [PATCH] drm: radeon: fix sign bug The "error" variable is unsigned so it's never less than zero. I changed it to check if (freq < current_freq) directly. "best_error" is also unsigned so "best_error - 100" could be a large number instead of a negative. Since "error" is unsigned it is never less than a negative and so the cases where "best_error" is less than or equal to 100 are false. Signed-off-by: Dan Carpenter Reviewed-by: Alex Deucher Signed-off-by: Dave Airlie --- drivers/gpu/drm/radeon/radeon_display.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c index 8154cdf796e..a68728dbd41 100644 --- a/drivers/gpu/drm/radeon/radeon_display.c +++ b/drivers/gpu/drm/radeon/radeon_display.c @@ -558,15 +558,17 @@ static void radeon_compute_pll_legacy(struct radeon_pll *pll, current_freq = radeon_div(tmp, ref_div * post_div); if (pll->flags & RADEON_PLL_PREFER_CLOSEST_LOWER) { - error = freq - current_freq; - error = error < 0 ? 0xffffffff : error; + if (freq < current_freq) + error = 0xffffffff; + else + error = freq - current_freq; } else error = abs(current_freq - freq); vco_diff = abs(vco - best_vco); if ((best_vco == 0 && error < best_error) || (best_vco != 0 && - (error < best_error - 100 || + ((best_error > 100 && error < best_error - 100) || (abs(error - best_error) < 100 && vco_diff < best_vco_diff)))) { best_post_div = post_div; best_ref_div = ref_div; -- 2.39.3