Re: [PATCH] drm/vc4: hdmi: Rely on interrupts to handle hotplug

On Mon, 24 May 2021 at 14:20, Maxime Ripard maxime@cerno.tech wrote:

DRM currently polls for the HDMI connector status every 10s, which can be an issue when we connect/disconnect a display quickly or the device on the other end only issues a hotplug pulse (for example on EDID change).

Switch the driver to rely on the internal controller logic for the BCM2711/RPi4.

Reviewed-by: Dave Stevenson dave.stevenson@raspberrypi.com

Signed-off-by: Maxime Ripard maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_hdmi.c | 44 ++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index c27b287d2053..3988969f7410 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -1510,6 +1510,46 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)

}

+static irqreturn_t vc4_hdmi_hpd_irq_thread(int irq, void *priv) +{

•   struct vc4_hdmi *vc4_hdmi = priv;
  

•   struct drm_device *dev = vc4_hdmi->connector.dev;
  

•   if (dev)
  

•           drm_kms_helper_hotplug_event(dev);
  

•   return IRQ_HANDLED;
  

+}

+static int vc4_hdmi_hotplug_init(struct vc4_hdmi *vc4_hdmi) +{

•   struct platform_device *pdev = vc4_hdmi->pdev;
  

•   struct device *dev = &pdev->dev;
  

•   int ret;
  

•   if (vc4_hdmi->variant->external_irq_controller) {
  

•           ret = devm_request_threaded_irq(dev,
  

•                                           platform_get_irq_byname(pdev, "hpd-connected"),
  

•                                           NULL,
  

•                                           vc4_hdmi_hpd_irq_thread, IRQF_ONESHOT,
  

•                                           "vc4 hdmi hpd connected", vc4_hdmi);
  

•           if (ret)
  

•                   return ret;
  

•           ret = devm_request_threaded_irq(dev,
  

•                                           platform_get_irq_byname(pdev, "hpd-removed"),
  

•                                           NULL,
  

•                                           vc4_hdmi_hpd_irq_thread, IRQF_ONESHOT,
  

•                                           "vc4 hdmi hpd disconnected", vc4_hdmi);
  

•           if (ret)
  

•                   return ret;
  

•           connector->polled = DRM_CONNECTOR_POLL_HPD;
  

•   }
  

•   return 0;
  

+}

#ifdef CONFIG_DRM_VC4_HDMI_CEC static irqreturn_t vc4_cec_irq_handler_rx_thread(int irq, void *priv) { @@ -2060,6 +2100,10 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data) if (ret) goto err_destroy_encoder;

•   ret = vc4_hdmi_hotplug_init(vc4_hdmi);
  

•   if (ret)
  

•           goto err_destroy_conn;
  

•   ret = vc4_hdmi_cec_init(vc4_hdmi);
    if (ret)
            goto err_destroy_conn;
  

-- 2.31.1