[Intel-gfx] [PATCH 1/2] drm/i915/edp: Get the Panel Power Off timestamp after panel is off

[Daniel Vetter]

On Tue, Oct 03, 2017 at 04:37:24PM -0700, Manasi Navare wrote:
> Kernel stores the time in jiffies at which the eDP panel is turned
> off. This should be obtained after the panel is off (after the
> wait_panel_off). When we next attempt to turn the panel on, we
> use the difference between the timestamp at which we want to turn the
> panel on and timestamp at which panel was turned off to ensure that this
> is equal to panel power cycle delay and if not we wait for the remaining
> time. Not waiting for the panel power cycle delay can cause the panel to not
> turn on giving rise to AUX timeouts for the attempted AUX transactions.
> 
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101518,
> https://bugs.freedesktop.org/show_bug.cgi?id=101144
> Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>

Nit: When someone else suggested a fix, it's nice to mention that in the
commit message. Either way:

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
>  drivers/gpu/drm/i915/intel_dp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 90e756c..0fd41cd 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -2308,8 +2308,8 @@ static void edp_panel_off(struct intel_dp *intel_dp)
>  	I915_WRITE(pp_ctrl_reg, pp);
>  	POSTING_READ(pp_ctrl_reg);
>  
> -	intel_dp->panel_power_off_time = ktime_get_boottime();
>  	wait_panel_off(intel_dp);
> +	intel_dp->panel_power_off_time = ktime_get_boottime();
>  
>  	/* We got a reference when we enabled the VDD. */
>  	intel_display_power_put(dev_priv, intel_dp->aux_power_domain);
> -- 
> 2.1.4
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch