diff options
| author |   Alex Deucher <alexdeucher@gmail.com> | 2009-07-13 11:08:18 -0400 |
|---|---|---|
| committer |   Dave Airlie <airlied@redhat.com> | 2009-07-15 17:13:22 +1000 |
| commit | d0e275a90a81b37409a0cfbca77581e3d235f5cf (patch) | |
| tree | 79a93ce519e39d1326bb23f38fa4549fc0950834 /drivers/gpu/drm/radeon/radeon_display.c | |
| parent | drm/radeon/kms: block RN50 from using 3D engine. (diff) | |
| download | linux-dev-d0e275a90a81b37409a0cfbca77581e3d235f5cf.tar.xz linux-dev-d0e275a90a81b37409a0cfbca77581e3d235f5cf.zip | |
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.c | 6 |
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 3efcf1a526be..bc312f3d9a0a 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) || |