Re: [PATCH] drm/i915: re-check the hotplug with a delayed work

From: Jani Nikula
Date: Wed Sep 19 2018 - 08:27:11 EST


On Wed, 19 Sep 2018, Chris Chiu <chiu@xxxxxxxxxxxx> wrote:
> I have few ASUS laptops, X705FD(Intel i7-8565), X560UD(Intel i5-8250U)
> and X530UN(Intel i7-8550U) share the same problem. The HDMI connector
> status stays 'connected' even the HDMI cable has been unplugged.
> Then the status in sysfs would never change since then until we
> do 'xrandr' to reprobe the devices. It would also cause the audio
> output path cannot correctly swicth based on the connector status.
>
> This commit kicks off a delayed work when the status remains unchanged
> in the first hotplug event handling, which may not be the perfect
> timing in some special cases.

Please see [1].

BR,
Jani.


[1] http://patchwork.freedesktop.org/patch/msgid/87k1nhy9ie.fsf@xxxxxxxxx

>
> Signed-off-by: Chris Chiu <chiu@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 1 +
> drivers/gpu/drm/i915/intel_hotplug.c | 35 +++++++++++++++++++++++++++++++----
> 2 files changed, 32 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index d51d8574a679..78e2cf09cc10 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -286,6 +286,7 @@ struct i915_hotplug {
> } stats[HPD_NUM_PINS];
> u32 event_bits;
> struct delayed_work reenable_work;
> + struct delayed_work recheck_work;
>
> struct intel_digital_port *irq_port[I915_MAX_PORTS];
> u32 long_port_mask;
> diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c
> index 43aa92beff2a..089a24588ec8 100644
> --- a/drivers/gpu/drm/i915/intel_hotplug.c
> +++ b/drivers/gpu/drm/i915/intel_hotplug.c
> @@ -349,14 +349,15 @@ static void i915_digport_work_func(struct work_struct *work)
> }
> }
>
> +#define HPD_RECHECK_DELAY (2 * 1000)
> +
> /*
> * Handle hotplug events outside the interrupt handler proper.
> */
> -static void i915_hotplug_work_func(struct work_struct *work)
> +static void do_i915_hotplug_check(struct work_struct *work,
> + struct drm_i915_private *dev_priv,
> + struct drm_device *dev, bool do_recheck)
> {
> - struct drm_i915_private *dev_priv =
> - container_of(work, struct drm_i915_private, hotplug.hotplug_work);
> - struct drm_device *dev = &dev_priv->drm;
> struct intel_connector *intel_connector;
> struct intel_encoder *intel_encoder;
> struct drm_connector *connector;
> @@ -396,8 +397,31 @@ static void i915_hotplug_work_func(struct work_struct *work)
>
> if (changed)
> drm_kms_helper_hotplug_event(dev);
> + else if (do_recheck) {
> + spin_lock_irq(&dev_priv->irq_lock);
> + dev_priv->hotplug.event_bits |= hpd_event_bits;
> + spin_unlock_irq(&dev_priv->irq_lock);
> + schedule_delayed_work(&dev_priv->hotplug.recheck_work, msecs_to_jiffies(HPD_RECHECK_DELAY));
> + }
> }
>
> +static void i915_hotplug_work_func(struct work_struct *work)
> +{
> + struct drm_i915_private *dev_priv =
> + container_of(work, struct drm_i915_private, hotplug.hotplug_work);
> + struct drm_device *dev = &dev_priv->drm;
> +
> + do_i915_hotplug_check(work, dev_priv, dev, true);
> +}
> +
> +static void i915_hotplug_recheck_func(struct work_struct *work)
> +{
> + struct drm_i915_private *dev_priv =
> + container_of(work, struct drm_i915_private, hotplug.recheck_work.work);
> + struct drm_device *dev = &dev_priv->drm;
> +
> + do_i915_hotplug_check(work, dev_priv, dev, false);
> +}
>
> /**
> * intel_hpd_irq_handler - main hotplug irq handler
> @@ -619,6 +643,8 @@ void intel_hpd_init_work(struct drm_i915_private *dev_priv)
> INIT_WORK(&dev_priv->hotplug.poll_init_work, i915_hpd_poll_init_work);
> INIT_DELAYED_WORK(&dev_priv->hotplug.reenable_work,
> intel_hpd_irq_storm_reenable_work);
> + INIT_DELAYED_WORK(&dev_priv->hotplug.recheck_work,
> + i915_hotplug_recheck_func);
> }
>
> void intel_hpd_cancel_work(struct drm_i915_private *dev_priv)
> @@ -635,6 +661,7 @@ void intel_hpd_cancel_work(struct drm_i915_private *dev_priv)
> cancel_work_sync(&dev_priv->hotplug.hotplug_work);
> cancel_work_sync(&dev_priv->hotplug.poll_init_work);
> cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work);
> + cancel_delayed_work_sync(&dev_priv->hotplug.recheck_work);
> }
>
> bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin)

--
Jani Nikula, Intel Open Source Graphics Center