[Intel-gfx] [PATCH v2 11/12] drm/i915/gen9: Add boot parameter for disabling DC6

[Imre Deak]

On ma, 2015-11-09 at 16:48 +0100, Patrik Jakobsson wrote:
> v2: Use _unsafe (Jani)
> 
> Signed-off-by: Patrik Jakobsson <patrik.jakobsson at 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 | 4 ++--
>  3 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h
> b/drivers/gpu/drm/i915/i915_drv.h
> index c0252ef..5628c5a 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_dc6;
>  	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..6457f3a 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_dc6 = 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_dc6, i915.enable_dc6, int, 0400);
> +MODULE_PARM_DESC(enable_dc6,
> +	"Enable power-saving display C-state 6. "
> +	"(0 = disable; 1 = enable [default])");
> +

It would be more generic to have something like enable_dc, -1=per-chip
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 95c3fcc..62c1273 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> @@ -708,7 +708,7 @@ 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_dc6)
>  		skl_enable_dc6(dev_priv);
>  	else
>  		gen9_enable_dc5(dev_priv);
> @@ -720,7 +720,7 @@ 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_dc6)
>  			gen9_set_dc_state(dev_priv,
> DC_STATE_EN_UPTO_DC6);
>  		else
>  			gen9_set_dc_state(dev_priv,
> DC_STATE_EN_UPTO_DC5);