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| author | Paulo Zanoni <paulo.r.zanoni@intel.com> | 2013-08-19 13:18:07 -0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2013-08-23 14:52:32 +0200 |
| commit | 215733fadb87709e91b3a622d786865292c9ab11 (patch) | |
| tree | aff961af369cae544c2d9e50415b8f04faad1d75 /drivers/gpu/drm | |
| parent | 3414caf63421762e57b26aa999e5187b42ee1606 (diff) | |
| download | op-kernel-dev-215733fadb87709e91b3a622d786865292c9ab11.zip op-kernel-dev-215733fadb87709e91b3a622d786865292c9ab11.tar.gz | |
drm/i915: grab force_wake when restoring LCPLL
If LCPLL is disabled, there's a chance we might be in package C8 state
or deeper, and we'll get a hard hang when restoring LCPLL (also, a red
led lights up on my motherboard). So grab the force_wake, which will
get us out of RC6 and, as a consequence, out of PC8+ (since we need
RC6 to get into PC8+).
Note: Discussions with hw designers are still ongoing what exactly
goes boom here. But I think we can go ahead and just merge this little
hack for now until it's clear what we actually need.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Add small note about the current state of the discussion
around this hack.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_display.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 7a40427..a2c8cb3 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6033,6 +6033,10 @@ void hsw_restore_lcpll(struct drm_i915_private *dev_priv) LCPLL_POWER_DOWN_ALLOW)) == LCPLL_PLL_LOCK) return; + /* Make sure we're not on PC8 state before disabling PC8, otherwise + * we'll hang the machine! */ + dev_priv->uncore.funcs.force_wake_get(dev_priv); + if (val & LCPLL_POWER_DOWN_ALLOW) { val &= ~LCPLL_POWER_DOWN_ALLOW; I915_WRITE(LCPLL_CTL, val); @@ -6060,6 +6064,8 @@ void hsw_restore_lcpll(struct drm_i915_private *dev_priv) LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1)) DRM_ERROR("Switching back to LCPLL failed\n"); } + + dev_priv->uncore.funcs.force_wake_put(dev_priv); } static void haswell_modeset_global_resources(struct drm_device *dev) |
