[Intel-gfx] [PATCH v2 1/2] drm/i915/edp: Get the Panel Power Off timestamp after panel is off

[Jani Nikula]

On Wed, 04 Oct 2017, Manasi Navare <manasi.d.navare at intel.com> 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.
>
> v2:
> * Separate lines for bugzilla (Jani Nikula)
> * Suggested by tag (Daniel Vetter)
>
> 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
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101144
> Suggested-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> Reviewed-by:  Daniel Vetter <daniel.vetter at ffwll.ch>
> Reviewed-by: Jani Nikula <jani.nikula at linux.intel.com>

Pushed both to dinq, with cc: stable on the first. Thanks for the
patches and the debugging efforts in particular!

---

Please do try to make it a habit to run checkpatch on your patches
before sending. We don't care about all of the more subjective warnings,
but then at least you make the conscious decision to ignore them.

I fixed these while applying:

-:13: WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per line)
#13: 
time. Not waiting for the panel power cycle delay can cause the panel to not

-:26: WARNING: Use a single space after Reviewed-by:
#26: 
Reviewed-by:  Daniel Vetter <daniel.vetter at ffwll.ch>

I use these to run checkpatch on the commits in my local tree before
sending:

alias checkpatch='checkpatch.pl -q --emacs --strict'

checkbranch()
{
    local commit
    local range

    if [ -z "$1" ]; then
	range="HEAD^..HEAD"
    elif [ -n "`echo $1 | grep '\.\.'`" ]; then
	range="$1"
    else
	range="$1..HEAD"
    fi

    for commit in `git rev-list --reverse $range`; do
	git --no-pager log --oneline -1 $commit
	git format-patch --stdout -1 $commit | checkpatch -
    done
}

and use like:

$ checkbranch $tip

where tip=drm-tip/drm-tip

I also have similar stuff to run sparse on every single series I send
out. Overall it's just so much more efficient to catch the trivial stuff
early rather than late. I also consider it a courtesy to my fellow
developers.


BR,
Jani.


> ---
>  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);

-- 
Jani Nikula, Intel Open Source Technology Center