[PATCH v3 11/12] drm/i915/gen9: Add boot parameter for disabling DC6

Patrik Jakobsson
2015-11-16T14:05:36Z

v2: Use _unsafe (Jani)
v3: Allow specifying specific DC-states instead of just DC6 (Imre)

Signed-off-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_params.c | 6 ++++++
drivers/gpu/drm/i915/intel_runtime_pm.c | 14 +++++++++++---
3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c0252ef..c85c1ec 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2639,6 +2639,7 @@ struct i915_params {
int panel_use_ssc;
int vbt_sdvo_panel_type;
int enable_rc6;
+ int enable_dc;
int enable_fbc;
int enable_ppgtt;
int enable_execlists;
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 368df67..ccc15c9 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -32,6 +32,7 @@ struct i915_params i915 __read_mostly = {
.panel_use_ssc = -1,
.vbt_sdvo_panel_type = -1,
.enable_rc6 = -1,
+ .enable_dc = -1,
.enable_fbc = -1,
.enable_execlists = -1,
.enable_hangcheck = true,
@@ -79,6 +80,11 @@ MODULE_PARM_DESC(enable_rc6,
"For example, 3 would enable rc6 and deep rc6, and 7 would enable everything. "
"default: -1 (use per-chip default)");

+module_param_named_unsafe(enable_dc, i915.enable_dc, int, 0400);
+MODULE_PARM_DESC(enable_dc,
+ "Enable power-saving display C-states. "
+ "(-1=auto [default]; 0=disable; 1=up to DC5; 2=up to DC6)");
+
module_param_named_unsafe(enable_fbc, i915.enable_fbc, int, 0600);
MODULE_PARM_DESC(enable_fbc,
"Enable frame buffer compression for power savings "
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index b6ee48e..4d6f777 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -417,6 +417,11 @@ static void gen9_set_dc_state(struct drm_i915_private *dev_priv, uint32_t state)

WARN_ON_ONCE(state & ~mask);

+ if (i915.enable_dc == 0)
+ state = DC_STATE_DISABLE;
+ else if (i915.enable_dc == 1 && state > DC_STATE_EN_UPTO_DC5)
+ state = DC_STATE_EN_UPTO_DC5;
+
if (state & DC_STATE_EN_UPTO_DC5_DC6_MASK)
gen9_set_dc_state_debugmask_memory_up(dev_priv);

@@ -524,7 +529,9 @@ static void assert_can_disable_dc6(struct drm_i915_private *dev_priv)
static void gen9_disable_dc5_dc6(struct drm_i915_private *dev_priv)
{
assert_can_disable_dc5(dev_priv);
- assert_can_disable_dc6(dev_priv);
+
+ if (IS_SKYLAKE(dev_priv) && i915.enable_dc != 0 && i915.enable_dc != 1)
+ assert_can_disable_dc6(dev_priv);

gen9_set_dc_state(dev_priv, DC_STATE_DISABLE);
}
@@ -709,7 +716,7 @@ static void gen9_dc_off_power_well_enable(struct drm_i915_private *dev_priv,
static void gen9_dc_off_power_well_disable(struct drm_i915_private *dev_priv,
struct i915_power_well *power_well)
{
- if (IS_SKYLAKE(dev_priv))
+ if (IS_SKYLAKE(dev_priv) && i915.enable_dc != 0 && i915.enable_dc != 1)
skl_enable_dc6(dev_priv);
else
gen9_enable_dc5(dev_priv);
@@ -721,7 +728,8 @@ static void gen9_dc_off_power_well_sync_hw(struct drm_i915_private *dev_priv,
if (power_well->count > 0) {
gen9_set_dc_state(dev_priv, DC_STATE_DISABLE);
} else {
- if (IS_SKYLAKE(dev_priv))
+ if (IS_SKYLAKE(dev_priv) && i915.enable_dc != 0 &&
+ i915.enable_dc != 1)
gen9_set_dc_state(dev_priv, DC_STATE_EN_UPTO_DC6);
else
gen9_set_dc_state(dev_priv, DC_STATE_EN_UPTO_DC5);
--
2.5.0