[PATCH] drm/i915: Make primary_enabled match the actual hardware state

ville.syrjala
2014-04-30T14:43:05Z

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

The BIOS can enable a pipe but leave the primary plane disabled. This
coflicts with out current idea of primary_enabled. Read the actual
hardware plane state and set primary_enabled appropriately.

We currently assume that primary_enabled is always true when we're about
to disable a crtc. That needs to change now as the plane may not be
enabled. So replace the relevant WARNs with early returns in
intel_{enable,disable}_primary_hw_plane().

Fixes the following warning
[ 3.831602] WARNING: CPU: 0 PID: 1112 at linux/drivers/gpu/drm/i915/intel_display.c:1918 intel_disable_primary_hw_plane+0xe4/0xf0 [i915]()

which got introduced here by me:
commit e9e39655c0c30cddc3f8c09a757678a24dd36737
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date: Mon Apr 28 15:53:25 2014 +0300

drm/i915: Remove useless checks from primary enable/disable

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/intel_display.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e1e1239..4b5c2d0 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1880,7 +1880,8 @@ static void intel_enable_primary_hw_plane(struct drm_i915_private *dev_priv,
/* If the pipe isn't enabled, we can't pump pixels and may hang */
assert_pipe_enabled(dev_priv, pipe);

- WARN(intel_crtc->primary_enabled, "Primary plane already enabled\n");
+ if (intel_crtc->primary_enabled)
+ return;

intel_crtc->primary_enabled = true;

@@ -1909,7 +1910,8 @@ static void intel_disable_primary_hw_plane(struct drm_i915_private *dev_priv,
int reg;
u32 val;

- WARN(!intel_crtc->primary_enabled, "Primary plane already disabled\n");
+ if (!intel_crtc->primary_enabled)
+ return;

intel_crtc->primary_enabled = false;

@@ -11584,6 +11586,16 @@ void i915_redisable_vga(struct drm_device *dev)
i915_redisable_vga_power_on(dev);
}

+static bool primary_get_hw_state(struct intel_crtc *crtc)
+{
+ struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+
+ if (!crtc->active)
+ return false;
+
+ return I915_READ(DSPCNTR(crtc->plane)) & DISPLAY_PLANE_ENABLE;
+}
+
static void intel_modeset_readout_hw_state(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
@@ -11603,7 +11615,7 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
&crtc->config);

crtc->base.enabled = crtc->active;
- crtc->primary_enabled = crtc->active;
+ crtc->primary_enabled = primary_get_hw_state(crtc);

DRM_DEBUG_KMS("[CRTC:%d] hw state readout: %s\n",
crtc->base.base.id,
--
1.8.3.2