Bug#597358: [PATCH 2.6.32.y-drm33.z 1/3] drm: radeon: fix sign bug
From: Dan Carpenter <error27@gmail.com>
Date: Sat, 17 Jul 2010 12:28:02 +0200
commit 167ffc44caaee68ea60dadf6931a4d195a4ed1f0 upstream.
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 <error27@gmail.com>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
drivers/gpu/drm/radeon/radeon_display.c | 8 +++++---
1 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 567bd8e1f3d0..22ed2171c67e 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -519,15 +519,17 @@ void radeon_compute_pll(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;
--
1.7.6
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