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drm/i915: add dynamic clock frequency control

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There are several sources of unnecessary power consumption on Intel
graphics systems. The first is the LVDS clock. TFTs don't suffer from
persistence issues like CRTs, and so we can reduce the LVDS refresh rate
when the screen is idle. It will be automatically upclocked when
userspace triggers graphical activity. Beyond that, we can enable memory
self refresh. This allows the memory to go into a lower power state when
the graphics are idle. Finally, we can drop some clocks on the gpu
itself. All of these things can be reenabled between frames when GPU
activity is triggered, and so there should be no user visible graphical
changes.

Signed-off-by: Jesse Barnes <jesse.barnes@intel.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
This commit is contained in:
Jesse Barnes
2009-08-17 13:31:43 -07:00
committed by Eric Anholt
parent 0430296558
commit 652c393a33
9 changed files with 704 additions and 45 deletions
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8
drivers/gpu/drm/i915/intel_bios.c
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@@ -355,8 +355,14 @@ parse_driver_features(struct drm_i915_private *dev_priv,
}
driver = find_section(bdb, BDB_DRIVER_FEATURES);
if (driver && driver->lvds_config == BDB_DRIVER_FEATURE_EDP)
if (!driver)
return;
if (driver->lvds_config == BDB_DRIVER_FEATURE_EDP)
dev_priv->edp_support = 1;
if (driver->dual_frequency)
dev_priv->render_reclock_avail = true;
}
/**