drm/i915: Disable C3 when enabling vblank interrupts on i945gm

[linux-2.6-microblaze.git] / drivers / gpu / drm / i915 / i915_irq.c

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 2f78829..fcbe173 100644 (file)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -30,6 +30,7 @@
 
 #include <linux/sysrq.h>
 #include <linux/slab.h>
+#include <linux/cpuidle.h>
 #include <linux/circ_buf.h>
 #include <drm/drm_irq.h>
 #include <drm/drm_drv.h>
@@ -3131,6 +3132,16 @@ static int i8xx_enable_vblank(struct drm_device *dev, unsigned int pipe)
        return 0;
 }
 
+static int i945gm_enable_vblank(struct drm_device *dev, unsigned int pipe)
+{
+       struct drm_i915_private *dev_priv = to_i915(dev);
+
+       if (dev_priv->i945gm_vblank.enabled++ == 0)
+               schedule_work(&dev_priv->i945gm_vblank.work);
+
+       return i8xx_enable_vblank(dev, pipe);
+}
+
 static int i965_enable_vblank(struct drm_device *dev, unsigned int pipe)
 {
        struct drm_i915_private *dev_priv = to_i915(dev);
@@ -3195,6 +3206,16 @@ static void i8xx_disable_vblank(struct drm_device *dev, unsigned int pipe)
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
 }
 
+static void i945gm_disable_vblank(struct drm_device *dev, unsigned int pipe)
+{
+       struct drm_i915_private *dev_priv = to_i915(dev);
+
+       i8xx_disable_vblank(dev, pipe);
+
+       if (--dev_priv->i945gm_vblank.enabled == 0)
+               schedule_work(&dev_priv->i945gm_vblank.work);
+}
+
 static void i965_disable_vblank(struct drm_device *dev, unsigned int pipe)
 {
        struct drm_i915_private *dev_priv = to_i915(dev);
@@ -3228,6 +3249,60 @@ static void gen8_disable_vblank(struct drm_device *dev, unsigned int pipe)
        spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
 }
 
+static void i945gm_vblank_work_func(struct work_struct *work)
+{
+       struct drm_i915_private *dev_priv =
+               container_of(work, struct drm_i915_private, i945gm_vblank.work);
+
+       /*
+        * Vblank interrupts fail to wake up the device from C3,
+        * hence we want to prevent C3 usage while vblank interrupts
+        * are enabled.
+        */
+       pm_qos_update_request(&dev_priv->i945gm_vblank.pm_qos,
+                             READ_ONCE(dev_priv->i945gm_vblank.enabled) ?
+                             dev_priv->i945gm_vblank.c3_disable_latency :
+                             PM_QOS_DEFAULT_VALUE);
+}
+
+static int cstate_disable_latency(const char *name)
+{
+       const struct cpuidle_driver *drv;
+       int i;
+
+       drv = cpuidle_get_driver();
+       if (!drv)
+               return 0;
+
+       for (i = 0; i < drv->state_count; i++) {
+               const struct cpuidle_state *state = &drv->states[i];
+
+               if (!strcmp(state->name, name))
+                       return state->exit_latency ?
+                               state->exit_latency - 1 : 0;
+       }
+
+       return 0;
+}
+
+static void i945gm_vblank_work_init(struct drm_i915_private *dev_priv)
+{
+       INIT_WORK(&dev_priv->i945gm_vblank.work,
+                 i945gm_vblank_work_func);
+
+       dev_priv->i945gm_vblank.c3_disable_latency =
+               cstate_disable_latency("C3");
+       pm_qos_add_request(&dev_priv->i945gm_vblank.pm_qos,
+                          PM_QOS_CPU_DMA_LATENCY,
+                          PM_QOS_DEFAULT_VALUE);
+}
+
+static void i945gm_vblank_work_fini(struct drm_i915_private *dev_priv)
+{
+       cancel_work_sync(&dev_priv->i945gm_vblank.work);
+       pm_qos_remove_request(&dev_priv->i945gm_vblank.pm_qos);
+}
+
 static void ibx_irq_reset(struct drm_i915_private *dev_priv)
 {
        if (HAS_PCH_NOP(dev_priv))
@@ -4525,6 +4600,9 @@ void intel_irq_init(struct drm_i915_private *dev_priv)
        struct intel_rps *rps = &dev_priv->gt_pm.rps;
        int i;
 
+       if (IS_I945GM(dev_priv))
+               i945gm_vblank_work_init(dev_priv);
+
        intel_hpd_init_work(dev_priv);
 
        INIT_WORK(&rps->work, gen6_pm_rps_work);
@@ -4647,6 +4725,13 @@ void intel_irq_init(struct drm_i915_private *dev_priv)
                        dev->driver->irq_uninstall = i8xx_irq_reset;
                        dev->driver->enable_vblank = i8xx_enable_vblank;
                        dev->driver->disable_vblank = i8xx_disable_vblank;
+               } else if (IS_I945GM(dev_priv)) {
+                       dev->driver->irq_preinstall = i915_irq_reset;
+                       dev->driver->irq_postinstall = i915_irq_postinstall;
+                       dev->driver->irq_uninstall = i915_irq_reset;
+                       dev->driver->irq_handler = i915_irq_handler;
+                       dev->driver->enable_vblank = i945gm_enable_vblank;
+                       dev->driver->disable_vblank = i945gm_disable_vblank;
                } else if (IS_GEN(dev_priv, 3)) {
                        dev->driver->irq_preinstall = i915_irq_reset;
                        dev->driver->irq_postinstall = i915_irq_postinstall;
@@ -4677,6 +4762,9 @@ void intel_irq_fini(struct drm_i915_private *i915)
 {
        int i;
 
+       if (IS_I945GM(i915))
+               i945gm_vblank_work_fini(i915);
+
        for (i = 0; i < MAX_L3_SLICES; ++i)
                kfree(i915->l3_parity.remap_info[i]);
 }