[SKL-DMC-BUGFIX 2/5] drm/i915/skl: Making DC6 entry is the last call in suspend flow.

Animesh Manna
2015-08-03T16:25:11Z

Mmio register access after dc6/dc5 entry is not allowed when
DC6 power states are enabled according to bspec (bspec-id 0527),
so enabling dc6 as the last call in suspend flow.

v1: Initial version.

v2: commit message updated based on comment from Vathsala.

Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: Vathsala Nagaraju <vathsala.nagaraju@intel.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@intel.com>
---
drivers/gpu/drm/i915/i915_drv.c | 12 ++++++------
drivers/gpu/drm/i915/intel_drv.h | 2 ++
drivers/gpu/drm/i915/intel_runtime_pm.c | 33 ++++++++-------------------------
3 files changed, 16 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 0d6775a..e1d0102 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1017,14 +1017,11 @@ static int skl_suspend_complete(struct drm_i915_private *dev_priv)
{
/* Enabling DC6 is not a hard requirement to enter runtime D3 */

- /*
- * This is to ensure that CSR isn't identified as loaded before
- * CSR-loading program is called during runtime-resume.
- */
- intel_csr_load_status_set(dev_priv, FW_UNINITIALIZED);
-
skl_uninit_cdclk(dev_priv);

+ if (intel_csr_load_status_get(dev_priv) == FW_LOADED)
+ skl_enable_dc6(dev_priv);
+
return 0;
}

@@ -1071,6 +1068,9 @@ static int skl_resume_prepare(struct drm_i915_private *dev_priv)
{
struct drm_device *dev = dev_priv->dev;

+ if (intel_csr_load_status_get(dev_priv) == FW_LOADED)
+ skl_disable_dc6(dev_priv);
+
skl_init_cdclk(dev_priv);
intel_csr_load_program(dev);

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 47cef0e..06f346f 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1117,6 +1117,8 @@ void bxt_enable_dc9(struct drm_i915_private *dev_priv);
void bxt_disable_dc9(struct drm_i915_private *dev_priv);
void skl_init_cdclk(struct drm_i915_private *dev_priv);
void skl_uninit_cdclk(struct drm_i915_private *dev_priv);
+void skl_enable_dc6(struct drm_i915_private *dev_priv);
+void skl_disable_dc6(struct drm_i915_private *dev_priv);
void intel_dp_get_m_n(struct intel_crtc *crtc,
struct intel_crtc_state *pipe_config);
void intel_dp_set_m_n(struct intel_crtc *crtc, enum link_m_n_set m_n);
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 6393b76..c660245 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -532,7 +532,7 @@ static void assert_can_disable_dc6(struct drm_i915_private *dev_priv)
"DC6 already programmed to be disabled.\n");
}

-static void skl_enable_dc6(struct drm_i915_private *dev_priv)
+void skl_enable_dc6(struct drm_i915_private *dev_priv)
{
uint32_t val;

@@ -549,7 +549,7 @@ static void skl_enable_dc6(struct drm_i915_private *dev_priv)
POSTING_READ(DC_STATE_EN);
}

-static void skl_disable_dc6(struct drm_i915_private *dev_priv)
+void skl_disable_dc6(struct drm_i915_private *dev_priv)
{
uint32_t val;

@@ -610,10 +610,10 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
!I915_READ(HSW_PWR_WELL_BIOS),
"Invalid for power well status to be enabled, unless done by the BIOS, \
when request is to disable!\n");
- if ((GEN9_ENABLE_DC5(dev) || SKL_ENABLE_DC6(dev)) &&
- power_well->data == SKL_DISP_PW_2) {
+ if (power_well->data == SKL_DISP_PW_2) {
+ if (GEN9_ENABLE_DC5(dev))
+ gen9_disable_dc5(dev_priv);
if (SKL_ENABLE_DC6(dev)) {
- skl_disable_dc6(dev_priv);
/*
* DDI buffer programming unnecessary during driver-load/resume
* as it's already done during modeset initialization then.
@@ -621,8 +621,6 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
*/
if (!dev_priv->power_domains.initializing)
intel_prepare_ddi(dev);
- } else {
- gen9_disable_dc5(dev_priv);
}
}
I915_WRITE(HSW_PWR_WELL_DRIVER, tmp | req_mask);
@@ -642,24 +640,9 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
POSTING_READ(HSW_PWR_WELL_DRIVER);
DRM_DEBUG_KMS("Disabling %s\n", power_well->name);

- if ((GEN9_ENABLE_DC5(dev) || SKL_ENABLE_DC6(dev)) &&
- power_well->data == SKL_DISP_PW_2) {
- enum csr_state state;
- /* TODO: wait for a completion event or
- * similar here instead of busy
- * waiting using wait_for function.
- */
- wait_for((state = intel_csr_load_status_get(dev_priv)) !=
- FW_UNINITIALIZED, 1000);
- if (state != FW_LOADED)
- DRM_ERROR("CSR firmware not ready (%d)\n",
- state);
- else
- if (SKL_ENABLE_DC6(dev))
- skl_enable_dc6(dev_priv);
- else
- gen9_enable_dc5(dev_priv);
- }
+ if (GEN9_ENABLE_DC5(dev) &&
+ power_well->data == SKL_DISP_PW_2)
+ gen9_enable_dc5(dev_priv);
}
}

--
2.0.2