On Tue, Oct 06, 2020 at 12:29:22PM +0300, Jani Nikula wrote:
> On Thu, 01 Oct 2020, Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> wrote:
> > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> >
> > Currently VLV/CHV use a reboot notifier to make sure the panel
> > power cycle delay isn't violated across a system reboot. Replace
> > that with the new encoder .shutdown() hook.
> >
> > And let's also stop overriding the power cycle delay with the
> > max value. No idea why the current code does that. The already
> > programmed delay should be correct.
>
> I kind of have a little uneasy feeling about conflating these two
> changes together. I think both are objectively good changes, just not
> necessarily at once.
>
> ISTR setting the max delay was, perhaps, somehow related to the hardware
> losing its marbles after power is cut, effectively not ensuring any of
> the delays at power-on. So it's possible we set the max here to account
> for that. Maybe. ;)
>
> Anyway,
>
> Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
>
> on the whole.
>
> I'm leaving it up to you, but personally I'd lean towards switching
> edp_notify_handler() to use wait_panel_power_cycle(intel_dp) first in a
> separate patch, to help with potential bisect results, and then doing
> the rest.
I don't think it would be quite that simple. We'd have to also toss
in some combination of panel_off() and vdd_off_sync() in there,
depending on whether the panel power is currently enabled or not.
Otherwise the bookkeeping needed by wait_panel_power_cycle() isn't
going to be up to date.
>
> >
> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > ---
> > .../drm/i915/display/intel_display_types.h | 2 -
> > drivers/gpu/drm/i915/display/intel_dp.c | 58 +++++--------------
> > 2 files changed, 14 insertions(+), 46 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> > index 6f3e3d756383..9b9ed1a2f412 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -1319,8 +1319,6 @@ struct intel_dp {
> > unsigned long last_backlight_off;
> > ktime_t panel_power_off_time;
> >
> > - struct notifier_block edp_notifier;
> > -
> > /*
> > * Pipe whose power sequencer is currently locked into
> > * this port. Only relevant on VLV/CHV.
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 70e0b85442f9..e0f2e9236785 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -28,7 +28,6 @@
> > #include <linux/export.h>
> > #include <linux/i2c.h>
> > #include <linux/notifier.h>
> > -#include <linux/reboot.h>
> > #include <linux/slab.h>
> > #include <linux/types.h>
> >
> > @@ -1191,41 +1190,6 @@ _pp_stat_reg(struct intel_dp *intel_dp)
> > return regs.pp_stat;
> > }
> >
> > -/* Reboot notifier handler to shutdown panel power to guarantee T12 timing
> > - This function only applicable when panel PM state is not to be tracked */
> > -static int edp_notify_handler(struct notifier_block *this, unsigned long code,
> > - void *unused)
> > -{
> > - struct intel_dp *intel_dp = container_of(this, typeof(* intel_dp),
> > - edp_notifier);
> > - struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > - intel_wakeref_t wakeref;
> > -
> > - if (!intel_dp_is_edp(intel_dp) || code != SYS_RESTART)
> > - return 0;
> > -
> > - with_pps_lock(intel_dp, wakeref) {
> > - if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
> > - enum pipe pipe = vlv_power_sequencer_pipe(intel_dp);
> > - i915_reg_t pp_ctrl_reg, pp_div_reg;
> > - u32 pp_div;
> > -
> > - pp_ctrl_reg = PP_CONTROL(pipe);
> > - pp_div_reg = PP_DIVISOR(pipe);
> > - pp_div = intel_de_read(dev_priv, pp_div_reg);
> > - pp_div &= PP_REFERENCE_DIVIDER_MASK;
> > -
> > - /* 0x1F write to PP_DIV_REG sets max cycle delay */
> > - intel_de_write(dev_priv, pp_div_reg, pp_div | 0x1F);
> > - intel_de_write(dev_priv, pp_ctrl_reg,
> > - PANEL_UNLOCK_REGS);
> > - msleep(intel_dp->panel_power_cycle_delay);
> > - }
> > - }
> > -
> > - return 0;
> > -}
> > -
> > static bool edp_have_panel_power(struct intel_dp *intel_dp)
> > {
> > struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > @@ -6690,11 +6654,6 @@ void intel_dp_encoder_flush_work(struct drm_encoder *encoder)
> > */
> > with_pps_lock(intel_dp, wakeref)
> > edp_panel_vdd_off_sync(intel_dp);
> > -
> > - if (intel_dp->edp_notifier.notifier_call) {
> > - unregister_reboot_notifier(&intel_dp->edp_notifier);
> > - intel_dp->edp_notifier.notifier_call = NULL;
> > - }
> > }
> >
> > intel_dp_aux_fini(intel_dp);
> > @@ -6725,6 +6684,18 @@ void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder)
> > edp_panel_vdd_off_sync(intel_dp);
> > }
> >
> > +static void intel_dp_encoder_shutdown(struct intel_encoder *intel_encoder)
> > +{
> > + struct intel_dp *intel_dp = enc_to_intel_dp(intel_encoder);
> > + intel_wakeref_t wakeref;
> > +
> > + if (!intel_dp_is_edp(intel_dp))
> > + return;
> > +
> > + with_pps_lock(intel_dp, wakeref)
> > + wait_panel_power_cycle(intel_dp);
> > +}
> > +
> > static void intel_edp_panel_vdd_sanitize(struct intel_dp *intel_dp)
> > {
> > struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > @@ -7838,9 +7809,6 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
> > mutex_unlock(&dev->mode_config.mutex);
> >
> > if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
> > - intel_dp->edp_notifier.notifier_call = edp_notify_handler;
> > - register_reboot_notifier(&intel_dp->edp_notifier);
> > -
> > /*
> > * Figure out the current pipe for the initial backlight setup.
> > * If the current pipe isn't valid, try the PPS pipe, and if that
> > @@ -8061,6 +8029,8 @@ bool intel_dp_init(struct drm_i915_private *dev_priv,
> > intel_encoder->get_config = intel_dp_get_config;
> > intel_encoder->update_pipe = intel_panel_update_backlight;
> > intel_encoder->suspend = intel_dp_encoder_suspend;
> > + if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> > + intel_encoder->shutdown = intel_dp_encoder_shutdown;
> > if (IS_CHERRYVIEW(dev_priv)) {
> > intel_encoder->pre_pll_enable = chv_dp_pre_pll_enable;
> > intel_encoder->pre_enable = chv_pre_enable_dp;
>
> --
> Jani Nikula, Intel Open Source Graphics Center
--
Ville Syrjälä
Intel
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