From 294c747be991a607deb37b2af15ebe2fc28ea9cc Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 11 Jan 2013 14:19:10 +0530 Subject: [PATCH] drm/i915: Periodically sanity check power management Every time we use the device after a period of idleness, check that the power management setup is still sane. This is to workaround a bug whereby it seems that we begin suppressing power management interrupts, preventing SandyBridge+ from going into turbo mode. This patch does have a side-effect. It removes the mark-busy for just moving the cursor - we don't want to increase the render clock just for the sprite, though we may want to bump the display frequency. I'd argue that we do not, and certainly don't want to take the struct_mutex here due to the large latencies that introduces. References: https://bugs.freedesktop.org/show_bug.cgi?id=44006 Signed-off-by: Chris Wilson Signed-off-by: Daniel Vetter v2: Backported and test on kernel 3.2.35 Signed-off-by: Gajanan Bhat --- drivers/gpu/drm/i915/i915_drv.h | 3 +++ drivers/gpu/drm/i915/intel_display.c | 43 ++++++++++++++++++++++++++++++++-- 2 files changed, 44 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 23086e8..54437bf 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -207,6 +207,7 @@ struct drm_i915_display_funcs { int (*get_display_clock_speed)(struct drm_device *dev); int (*get_fifo_size)(struct drm_device *dev, int plane); void (*update_wm)(struct drm_device *dev); + void (*sanitize_pm)(struct drm_device *dev); int (*crtc_mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode, @@ -1366,6 +1367,8 @@ void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv); void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv); void __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv); +void intel_sanitize_pm(struct drm_device *dev); + /* We give fast paths for the really cool registers */ #define NEEDS_FORCE_WAKE(dev_priv, reg) \ (((dev_priv)->info->gen >= 6) && \ diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 19b0d8d..1f2e837 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6844,9 +6844,10 @@ void intel_mark_busy(struct drm_device *dev, struct drm_i915_gem_object *obj) if (!drm_core_check_feature(dev, DRIVER_MODESET)) return; - if (!dev_priv->busy) + if (!dev_priv->busy) { + intel_sanitize_pm(dev); dev_priv->busy = true; - else + } else mod_timer(&dev_priv->idle_timer, jiffies + msecs_to_jiffies(GPU_IDLE_TIMEOUT)); @@ -8607,6 +8608,42 @@ void intel_init_clock_gating(struct drm_device *dev) dev_priv->display.init_pch_clock_gating(dev); } +static void gen6_sanitize_pm(struct drm_device *dev) +{ + struct drm_i915_private *dev_priv = dev->dev_private; + u32 limits, delay, old; + + gen6_gt_force_wake_get(dev_priv); + + old = limits = I915_READ(GEN6_RP_INTERRUPT_LIMITS); + /* Make sure we continue to get interrupts + * until we hit the minimum or maximum frequencies. + */ + limits &= ~(0x3f << 16 | 0x3f << 24); + delay = dev_priv->cur_delay; + if (delay < dev_priv->max_delay) + limits |= (dev_priv->max_delay & 0x3f) << 24; + if (delay > dev_priv->min_delay) + limits |= (dev_priv->min_delay & 0x3f) << 16; + + if (old != limits) { + DRM_ERROR("Power management discrepancy: GEN6_RP_INTERRUPT_LIMITS expected %08x, was %08x\n", + limits, old); + I915_WRITE(GEN6_RP_INTERRUPT_LIMITS, limits); + } + + gen6_gt_force_wake_put(dev_priv); +} + +void intel_sanitize_pm(struct drm_device *dev) +{ + struct drm_i915_private *dev_priv = dev->dev_private; + + if (dev_priv->display.sanitize_pm) + dev_priv->display.sanitize_pm(dev); +} + + /* Set up chip specific display functions */ static void intel_init_display(struct drm_device *dev) { @@ -8713,6 +8750,7 @@ static void intel_init_display(struct drm_device *dev) } dev_priv->display.fdi_link_train = gen6_fdi_link_train; dev_priv->display.init_clock_gating = gen6_init_clock_gating; + dev_priv->display.sanitize_pm = gen6_sanitize_pm; dev_priv->display.write_eld = ironlake_write_eld; } else if (IS_IVYBRIDGE(dev)) { /* FIXME: detect B0+ stepping and use auto training */ @@ -8725,6 +8763,7 @@ static void intel_init_display(struct drm_device *dev) dev_priv->display.update_wm = NULL; } dev_priv->display.init_clock_gating = ivybridge_init_clock_gating; + dev_priv->display.sanitize_pm = gen6_sanitize_pm; dev_priv->display.write_eld = ironlake_write_eld; } else dev_priv->display.update_wm = NULL; -- 1.7.9.5