On Tue, 2018-10-30 at 19:52 +0200, Ville Syrjälä wrote:
> On Wed, Oct 10, 2018 at 02:35:07PM -0700, José Roberto de Souza
> wrote:
> > Some USB type-C dongles requires some time to power on before being
> > able to process aux channel transactions.
> > It was not a problem for older gens because there was a bridge
> > between DP port and USB-C controller adding some delay but ICL
> > handles type-C native.
> >
> > So here trying to do a aux channel transaction at each 150ms for up
> > 5
> > times, before giving up.
> >
> > Cc: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
> > Signed-off-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/i915_drv.h | 1 +
> > drivers/gpu/drm/i915/intel_dp.c | 7 ++++
> > drivers/gpu/drm/i915/intel_drv.h | 6 ++-
> > drivers/gpu/drm/i915/intel_hotplug.c | 58
> > ++++++++++++++++++++++++++++
> > 4 files changed, 71 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > b/drivers/gpu/drm/i915/i915_drv.h
> > index 3017ef037fed..b3f1fc865366 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -2810,6 +2810,7 @@ enum hpd_pin intel_hpd_pin_default(struct
> > drm_i915_private *dev_priv,
> > enum port port);
> > bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum
> > hpd_pin pin);
> > void intel_hpd_enable(struct drm_i915_private *dev_priv, enum
> > hpd_pin pin);
> > +void intel_hotplug_tc_wa_work(struct work_struct *__work);
> >
> > /* i915_irq.c */
> > static inline void i915_queue_hangcheck(struct drm_i915_private
> > *dev_priv)
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > b/drivers/gpu/drm/i915/intel_dp.c
> > index 60e62a3c1e22..b945385cd5bc 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -5289,6 +5289,7 @@ void intel_dp_encoder_destroy(struct
> > drm_encoder *encoder)
> > {
> > struct intel_digital_port *intel_dig_port =
> > enc_to_dig_port(encoder);
> > struct intel_dp *intel_dp = &intel_dig_port->dp;
> > + struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> >
> > intel_dp_mst_encoder_cleanup(intel_dig_port);
> > if (intel_dp_is_edp(intel_dp)) {
> > @@ -5305,6 +5306,8 @@ void intel_dp_encoder_destroy(struct
> > drm_encoder *encoder)
> > unregister_reboot_notifier(&intel_dp-
> > >edp_notifier);
> > intel_dp->edp_notifier.notifier_call = NULL;
> > }
> > + } else if (IS_ICELAKE(dev_priv)) {
> > + cancel_delayed_work_sync(&intel_dp->tc_wa_work);
> > }
> >
> > intel_dp_aux_fini(intel_dp);
> > @@ -6663,6 +6666,10 @@ intel_dp_init_connector(struct
> > intel_digital_port *intel_dig_port,
> > I915_WRITE(PEG_BAND_GAP_DATA, (temp & ~0xf) | 0xd);
> > }
> >
> > + if (IS_ICELAKE(dev_priv) && !intel_dp_is_edp(intel_dp))
> > + INIT_DELAYED_WORK(&intel_dp->tc_wa_work,
> > + intel_hotplug_tc_wa_work);
> > +
> > return true;
> >
> > fail:
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > b/drivers/gpu/drm/i915/intel_drv.h
> > index 3dea7a1bda7f..174a54aa966a 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1100,7 +1100,11 @@ struct intel_dp {
> > int panel_power_cycle_delay;
> > int backlight_on_delay;
> > int backlight_off_delay;
> > - struct delayed_work panel_vdd_work;
> > + union {
> > + struct delayed_work panel_vdd_work;
> > + struct delayed_work tc_wa_work;
> > + };
> > + u8 tc_wa_count;
> > bool want_panel_vdd;
> > unsigned long last_power_on;
> > unsigned long last_backlight_off;
> > diff --git a/drivers/gpu/drm/i915/intel_hotplug.c
> > b/drivers/gpu/drm/i915/intel_hotplug.c
> > index 648a13c6043c..96546067f832 100644
> > --- a/drivers/gpu/drm/i915/intel_hotplug.c
> > +++ b/drivers/gpu/drm/i915/intel_hotplug.c
> > @@ -323,6 +323,45 @@ static void i915_digport_work_func(struct
> > work_struct *work)
> > }
> > }
> >
> > +#define TC_WA_DELAY_MSEC 150
> > +#define TC_WA_TRIES 5
> > +
> > +void intel_hotplug_tc_wa_work(struct work_struct *__work)
> > +{
> > + struct intel_dp *intel_dp =
> > container_of(to_delayed_work(__work),
> > + struct intel_dp,
> > tc_wa_work);
> > + struct intel_digital_port *intel_dig_port =
> > dp_to_dig_port(intel_dp);
> > + struct intel_encoder *intel_encoder = &intel_dig_port->base;
> > + struct intel_connector *intel_connector = intel_dp-
> > >attached_connector;
> > + struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > + struct drm_device *dev = &dev_priv->drm;
> > + u8 val;
> > +
> > + if (!intel_port_is_tc(dev_priv, intel_encoder->port) ||
> > + !intel_digital_port_connected(intel_encoder))
> > + return;
> > +
> > + if (drm_dp_dpcd_read(&intel_dp->aux, DP_DPCD_REV, &val, 1) < 1)
> > {
> > + intel_dp->tc_wa_count++;
> > +
> > + if (intel_dp->tc_wa_count < TC_WA_TRIES) {
> > + unsigned long delay;
> > +
> > + delay = msecs_to_jiffies(TC_WA_DELAY_MSEC);
> > + schedule_delayed_work(&intel_dp->tc_wa_work,
> > delay);
> > + } else {
> > + DRM_DEBUG_KMS("TC not responsive, giving
> > up\n");
> > + }
> > + } else {
> > + mutex_lock(&dev->mode_config.mutex);
> > + val = intel_encoder->hotplug(intel_encoder,
> > intel_connector);
> > + mutex_unlock(&dev->mode_config.mutex);
> > +
> > + if (val)
> > + drm_kms_helper_hotplug_event(dev);
> > + }
> > +}
> > +
> > /*
> > * Handle hotplug events outside the interrupt handler proper.
> > */
> > @@ -361,6 +400,25 @@ static void i915_hotplug_work_func(struct
> > work_struct *work)
> > DRM_DEBUG_KMS("Connector %s (pin %i) received
> > hotplug event.\n",
> > connector->name, intel_encoder-
> > >hpd_pin);
> >
> > + /*
> > + * TC WA: TC dongles takes some type to be
> > + * responsible
> > + */
> > + if (IS_ICELAKE(dev_priv) &&
> > + intel_port_is_tc(dev_priv, intel_encoder-
> > >port) &&
> > + intel_digital_port_connected(intel_encoder)
> > ) {
> > + struct intel_dp *intel_dp;
> > + unsigned long delay;
> > +
> > + intel_dp =
> > enc_to_intel_dp(&intel_encoder->base);
> > +
> > + intel_dp->tc_wa_count = 0;
> > + delay =
> > msecs_to_jiffies(TC_WA_DELAY_MSEC);
> > + schedule_delayed_work(&intel_dp-
> > >tc_wa_work,
> > + delay);
> > + continue;
> > + }
> > +
> > changed |= intel_encoder-
> > >hotplug(intel_encoder,
> > intel_connect
> > or);
>
> I think if we need such duct-tape we should just stuff it into the
> .hotplug() hook.
The problem of moving it to intel_encoder_hotplug() is avoid infinite
tries in case the transaction inside of intel_encoder_hotplug() fails
after the one in intel_hotplug_tc_wa_work() works:
intel_hotplug_tc_wa_work()
{
...
intel_dp->tc_wa_count++
if (drm_dp_dpcd_read() == 1)
intel_encoder_hotplug()
...
}
intel_encoder_hotplug()
{
...
if (drm_dp_dpcd_read() < 1)
if (IS_ICELAKE() && intel_port_is_tc() &&
intel_digital_port_connected())
intel_dp->tc_wa_count = 0;
schedule_delayed_work()
...
}
I'm still thinking about other solutions but I guess the safest place
is i915_hotplug_work_func(), any other tip?
>
> > }
> > --
> > 2.19.1
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
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