[PATCH v3 4/5] drm/i915: make sure VDD is turned off during system suspend

Imre Deak
2014-08-18T11:47:24Z

Atm we may leave eDP VDD enabled during system suspend after the CRTCs
are disabled through an HPD->DPCD read event. So disable VDD during
suspend at a point when no HPDs can occur.

Note that runtime suspend doesn't have the same problem, since there the
RPM ref held by VDD provides already the needed serialization.

v2:
- add note to commit message about the runtime suspend path (Ville)
- use edp_panel_vdd_off_sync(), so we can keep the WARN in
edp_panel_vdd_off() (Ville)
v3:
- rebased on -fixes (for_each_intel_encoder()->list_for_each_entry())
(Imre)

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v2)
[rebased on -fixes (Imre)] (v3)
---
drivers/gpu/drm/i915/i915_drv.c | 17 +++++++++++++++++
drivers/gpu/drm/i915/intel_dp.c | 11 +++++++++++
drivers/gpu/drm/i915/intel_drv.h | 6 ++++++
3 files changed, 34 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 3f9c8f6..e27cdbe 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -509,6 +509,21 @@ void intel_hpd_cancel_work(struct drm_i915_private *dev_priv)
cancel_delayed_work_sync(&dev_priv->hotplug_reenable_work);
}

+static void intel_suspend_encoders(struct drm_i915_private *dev_priv)
+{
+ struct drm_device *dev = dev_priv->dev;
+ struct drm_encoder *encoder;
+
+ drm_modeset_lock_all(dev);
+ list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
+ struct intel_encoder *intel_encoder = to_intel_encoder(encoder);
+
+ if (intel_encoder->suspend)
+ intel_encoder->suspend(intel_encoder);
+ }
+ drm_modeset_unlock_all(dev);
+}
+
static int i915_drm_freeze(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
@@ -555,6 +570,8 @@ static int i915_drm_freeze(struct drm_device *dev)
intel_runtime_pm_disable_interrupts(dev);
intel_hpd_cancel_work(dev_priv);

+ intel_suspend_encoders(dev_priv);
+
intel_suspend_gt_powersave(dev);

intel_modeset_suspend_hw(dev);
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index a520188..e31ac9e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4003,6 +4003,16 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
kfree(intel_dig_port);
}

+void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder)
+{
+ struct intel_dp *intel_dp = enc_to_intel_dp(&intel_encoder->base);
+
+ if (!is_edp(intel_dp))
+ return;
+
+ edp_panel_vdd_off_sync(intel_dp);
+}
+
static void intel_dp_encoder_reset(struct drm_encoder *encoder)
{
intel_edp_panel_vdd_sanitize(to_intel_encoder(encoder));
@@ -4731,6 +4741,7 @@ intel_dp_init(struct drm_device *dev, int output_reg, enum port port)
intel_encoder->disable = intel_disable_dp;
intel_encoder->get_hw_state = intel_dp_get_hw_state;
intel_encoder->get_config = intel_dp_get_config;
+ intel_encoder->suspend = intel_dp_encoder_suspend;
if (IS_CHERRYVIEW(dev)) {
intel_encoder->pre_pll_enable = chv_dp_pre_pll_enable;
intel_encoder->pre_enable = chv_pre_enable_dp;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index fe3431f..b8c8bbd 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -153,6 +153,12 @@ struct intel_encoder {
* be set correctly before calling this function. */
void (*get_config)(struct intel_encoder *,
struct intel_crtc_config *pipe_config);
+ /*
+ * Called during system suspend after all pending requests for the
+ * encoder are flushed (for example for DP AUX transactions) and
+ * device interrupts are disabled.
+ */
+ void (*suspend)(struct intel_encoder *);
int crtc_mask;
enum hpd_pin hpd_pin;
};