drm/i915: simplify rps interrupt enabling/disabling sequence

At the moment we have the following interrupt enabling sequence:
1. irq preinstall hook
2. enabling the interrupt handler and calling irq postinstall hook
3. enable rps interrupts from the async work

And the folliwing disable sequence:
1. disabling the interrupt handler and calling the uninstall hook
2. disabling the rps interrupt

Since the postinstall hook now always sets up PMIIR, PMIER and PMIMR
to known-good states there no way for an interrupt to sneak in in the
enable sequence, so we can reinstate the WARN lost in

commit eda63ffb906c2fb3b609a0e87aeb63c0f25b9e6b
Author: Ben Widawsky <ben@bwidawsk.net>
Date:   Tue May 28 19:22:26 2013 -0700

    drm/i915: Add PM regs to pre/post install

Note that there's some room for future cleanups since most of the
interrupt register clearing in the disable function is rather
redundant. But that's better done in follow-up patches, if at all.

Cc: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 787a528e7200afd175973dbd1a0eb9a1c6d66be3..bc5aae088550e8b86b8efc53ba9bcbeeb578953c 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3193,9 +3193,7 @@ static void gen6_enable_rps_interrupts(struct drm_device *dev)
        struct drm_i915_private *dev_priv = dev->dev_private;
 
        spin_lock_irq(&dev_priv->irq_lock);
-       /* FIXME: Our interrupt enabling sequence is bonghits.
-        * dev_priv->rps.pm_iir really should be 0 here. */
-       dev_priv->rps.pm_iir = 0;
+       WARN_ON(dev_priv->rps.pm_iir);
        I915_WRITE(GEN6_PMIMR, I915_READ(GEN6_PMIMR) & ~GEN6_PM_RPS_EVENTS);
        I915_WRITE(GEN6_PMIIR, GEN6_PM_RPS_EVENTS);
        spin_unlock_irq(&dev_priv->irq_lock);