drm/i915: Check mask/bit helper functions

After a bit of irc discussion we've concluded that it would be prudent
to check that callers use the mask/enable paramters correctly. So add
a WARN_ON.

Spurred by Damien's bugfix which added _MASKED_FIELD.

v2: We use WARN_ON(1) a lot to catch default cases in switch blocks
which should always be extended. So this doesn't work really. Dunno
why gcc only started complaining when I've moved the WARN out of the
static inline helper to address a feedback from Jani.

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 08a5a4ba52acd027c27e5559539593f283ad0cc3..e6a1db36928e977e238df41731a99854a2c8ce69 100644 (file)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -183,6 +183,8 @@ static void ilk_update_gt_irq(struct drm_i915_private *dev_priv,
 {
        assert_spin_locked(&dev_priv->irq_lock);
 
+       WARN_ON(enabled_irq_mask & ~interrupt_mask);
+
        if (WARN_ON(!intel_irqs_enabled(dev_priv)))
                return;
 
@@ -229,6 +231,8 @@ static void snb_update_pm_irq(struct drm_i915_private *dev_priv,
 {
        uint32_t new_val;
 
+       WARN_ON(enabled_irq_mask & ~interrupt_mask);
+
        assert_spin_locked(&dev_priv->irq_lock);
 
        new_val = dev_priv->pm_irq_mask;
@@ -328,6 +332,8 @@ void ibx_display_interrupt_update(struct drm_i915_private *dev_priv,
        sdeimr &= ~interrupt_mask;
        sdeimr |= (~enabled_irq_mask & interrupt_mask);
 
+       WARN_ON(enabled_irq_mask & ~interrupt_mask);
+
        assert_spin_locked(&dev_priv->irq_lock);
 
        if (WARN_ON(!intel_irqs_enabled(dev_priv)))