drm/i915: don't disable the power well yet

We're still not 100% ready to disable the power well, so don't disable
it for now. When we disable it we break the audio driver (because some
of the audio registers are on the power well) and machines with eDP on
port D (because it doesn't use TRANSCODER_EDP).

Also, instead of just reverting the code, add a Kernel option to let
us disable it if we want. This will allow us to keep developing and
testing the feature while it's not enabled.

This fixes problems caused by the following commit:
  commit d6dd9eb1d96d2b7345fe4664066c2b7ed86da898
  Author: Daniel Vetter <daniel.vetter@ffwll.ch>
  Date:   Tue Jan 29 16:35:20 2013 -0200
       drm/i915: dynamic Haswell display power well support

References: http://www.mail-archive.com/intel-gfx@lists.freedesktop.org/msg18788.html
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Mengdong Lin <mengdong.lin@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 0a8eceb7590244af233d153845a91c79e6662420..e9b57893db2b1ebba1348a71e37c845f98c3286b 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -125,6 +125,11 @@ MODULE_PARM_DESC(preliminary_hw_support,
                "Enable Haswell and ValleyView Support. "
                "(default: false)");
 
+int i915_disable_power_well __read_mostly = 0;
+module_param_named(disable_power_well, i915_disable_power_well, int, 0600);
+MODULE_PARM_DESC(disable_power_well,
+                "Disable the power well when possible (default: false)");
+
 static struct drm_driver driver;
 extern int intel_agp_enabled;
 

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e95337c974594d34c936d071975f5040c78754d1..01769e2a99538e9e99cd191b328d7746439d328b 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1398,6 +1398,7 @@ extern int i915_enable_fbc __read_mostly;
 extern bool i915_enable_hangcheck __read_mostly;
 extern int i915_enable_ppgtt __read_mostly;
 extern unsigned int i915_preliminary_hw_support __read_mostly;
+extern int i915_disable_power_well __read_mostly;
 
 extern int i915_suspend(struct drm_device *dev, pm_message_t state);
 extern int i915_resume(struct drm_device *dev);

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index a1794c6df1bf1b80917f60e2145c39ae741aa478..adca00783e61b304723d3d05197b53f47b6b33db 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4079,6 +4079,9 @@ void intel_set_power_well(struct drm_device *dev, bool enable)
        if (!IS_HASWELL(dev))
                return;
 
+       if (!i915_disable_power_well && !enable)
+               return;
+
        tmp = I915_READ(HSW_PWR_WELL_DRIVER);
        is_enabled = tmp & HSW_PWR_WELL_STATE;
        enable_requested = tmp & HSW_PWR_WELL_ENABLE;