diff options
| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2015-03-05 21:19:43 +0200 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-03-17 22:30:02 +0100 |
| commit | abfc00b545ba2c4dee1dcb124be59f34df3ed7d9 (patch) | |
| tree | b235093e7f033a20ec8e176e734c416c44a13ff6 /drivers/gpu/drm/i915/intel_pm.c | |
| parent | 120305166aa8da2e8166d7ac1adce30194e6e24f (diff) | |
| download | lwn-abfc00b545ba2c4dee1dcb124be59f34df3ed7d9.tar.gz lwn-abfc00b545ba2c4dee1dcb124be59f34df3ed7d9.zip | |
drm/i915: Simplify VLV drain latency computation
The current drain lantency computation relies on hardcoded limits to
determine when the to use the low vs. high precision multiplier.
Rewrite the code to use a more straightforward approach.
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_pm.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_pm.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index cc3c2d9eb7f4..c198dbad3e82 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -755,12 +755,15 @@ static bool vlv_compute_drain_latency(struct drm_crtc *crtc, return false; entries = DIV_ROUND_UP(clock, 1000) * pixel_size; - if (IS_CHERRYVIEW(dev)) - *prec_mult = (entries > 32) ? 16 : 8; - else - *prec_mult = (entries > 128) ? 64 : 32; + + *prec_mult = IS_CHERRYVIEW(dev) ? 16 : 64; *drain_latency = (64 * (*prec_mult) * 4) / entries; + if (*drain_latency > DRAIN_LATENCY_MASK) { + *prec_mult /= 2; + *drain_latency = (64 * (*prec_mult) * 4) / entries; + } + if (*drain_latency > DRAIN_LATENCY_MASK) *drain_latency = DRAIN_LATENCY_MASK; |