[Intel-gfx] [PATCH v4] drm/i915: edp resume/On time optimization.

[Kumar, Shobhit]

On 01/13/2016 07:27 AM, abhay.kumar at intel.com wrote:
> From: Abhay Kumar <abhay.kumar at intel.com>
>
> Make resume/on codepath not to wait for panel_power_cycle_delay(t11_t12)
> if this time is already spent in suspend/poweron time.
>
> v2: Use CLOCK_BOOTTIME and remove jiffies for panel power cycle
>      delay calculation(Ville).
>
> v3: Addressed below comments
>      1. Tracking time from where last powercycle is initiated.
>      2. Used ktime_get_bootime() wrapper for boottime clock.
>      3. Used ktime_ms_delta() to get time difference.
>
> v4: Updated v3 change log in detail.

Quick tip, you can use --in-reply-to while sending to maintain context, 
unless there is major rewrite of patches.

Regards
Shobhit

>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Abhay Kumar <abhay.kumar at intel.com>
> ---
>   drivers/gpu/drm/i915/intel_dp.c  | 19 ++++++++++++++-----
>   drivers/gpu/drm/i915/intel_drv.h |  2 +-
>   2 files changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 796e3d3..0042693 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1812,12 +1812,21 @@ static void wait_panel_off(struct intel_dp *intel_dp)
>
>   static void wait_panel_power_cycle(struct intel_dp *intel_dp)
>   {
> +	static ktime_t panel_power_on_time;
> +	s64 panel_power_off_duration;
> +
>   	DRM_DEBUG_KMS("Wait for panel power cycle\n");
>
> +	/* take the difference of currrent time and panel power off time
> +	 * and then make panel wait for t11_t12 if needed. */
> +	panel_power_on_time = ktime_get_boottime();
> +	panel_power_off_duration = ktime_ms_delta(panel_power_on_time, intel_dp->panel_power_off_time);
> +
>   	/* When we disable the VDD override bit last we have to do the manual
>   	 * wait. */
> -	wait_remaining_ms_from_jiffies(intel_dp->last_power_cycle,
> -				       intel_dp->panel_power_cycle_delay);
> +	if (panel_power_off_duration < (s64)intel_dp->panel_power_cycle_delay)
> +		wait_remaining_ms_from_jiffies(jiffies,
> +				       intel_dp->panel_power_cycle_delay - panel_power_off_duration);
>
>   	wait_panel_status(intel_dp, IDLE_CYCLE_MASK, IDLE_CYCLE_VALUE);
>   }
> @@ -1969,7 +1978,7 @@ static void edp_panel_vdd_off_sync(struct intel_dp *intel_dp)
>   	I915_READ(pp_stat_reg), I915_READ(pp_ctrl_reg));
>
>   	if ((pp & POWER_TARGET_ON) == 0)
> -		intel_dp->last_power_cycle = jiffies;
> +		intel_dp->panel_power_off_time = ktime_get_boottime();
>
>   	power_domain = intel_display_port_aux_power_domain(intel_encoder);
>   	intel_display_power_put(dev_priv, power_domain);
> @@ -2118,7 +2127,7 @@ static void edp_panel_off(struct intel_dp *intel_dp)
>   	I915_WRITE(pp_ctrl_reg, pp);
>   	POSTING_READ(pp_ctrl_reg);
>
> -	intel_dp->last_power_cycle = jiffies;
> +	intel_dp->panel_power_off_time = ktime_get_boottime();
>   	wait_panel_off(intel_dp);
>
>   	/* We got a reference when we enabled the VDD. */
> @@ -5122,7 +5131,7 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
>
>   static void intel_dp_init_panel_power_timestamps(struct intel_dp *intel_dp)
>   {
> -	intel_dp->last_power_cycle = jiffies;
> +	intel_dp->panel_power_off_time = ktime_get_boottime();
>   	intel_dp->last_power_on = jiffies;
>   	intel_dp->last_backlight_off = jiffies;
>   }
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index bdfe403..06b37b8 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -793,9 +793,9 @@ struct intel_dp {
>   	int backlight_off_delay;
>   	struct delayed_work panel_vdd_work;
>   	bool want_panel_vdd;
> -	unsigned long last_power_cycle;
>   	unsigned long last_power_on;
>   	unsigned long last_backlight_off;
> +	ktime_t panel_power_off_time;
>
>   	struct notifier_block edp_notifier;
>
>