aboutsummaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/radeon/radeon_display.c
diff options
context:
space:
mode:
authorAlex Deucher <alexdeucher@gmail.com>2009-07-13 11:08:18 -0400
committerDave Airlie <airlied@redhat.com>2009-07-15 17:13:22 +1000
commitd0e275a90a81b37409a0cfbca77581e3d235f5cf (patch)
tree79a93ce519e39d1326bb23f38fa4549fc0950834 /drivers/gpu/drm/radeon/radeon_display.c
parentb995e4330de0d8b1b8b9e49ce10cc6dc78e2cbba (diff)
drm/radeon/kms: add PLL flag to prefer frequencies <= the target freq
This is needed when using fractional feedback dividers on some IGP chips. Signed-off-by: Alex Deucher <alexdeucher@gmail.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/radeon/radeon_display.c')
-rw-r--r--drivers/gpu/drm/radeon/radeon_display.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 3efcf1a526b..bc312f3d9a0 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -491,7 +491,11 @@ void radeon_compute_pll(struct radeon_pll *pll,
tmp += (uint64_t)pll->reference_freq * 1000 * frac_feedback_div;
current_freq = radeon_div(tmp, ref_div * post_div);
- error = abs(current_freq - freq);
+ if (flags & RADEON_PLL_PREFER_CLOSEST_LOWER) {
+ error = freq - current_freq;
+ error = error < 0 ? 0xffffffff : error;
+ } else
+ error = abs(current_freq - freq);
vco_diff = abs(vco - best_vco);
if ((best_vco == 0 && error < best_error) ||