From 8d40b03821362d445a03dc23475fc4dff3ba88a7 Mon Sep 17 00:00:00 2001 From: Dom Cobley Date: Tue, 23 Apr 2024 17:30:56 +0100 Subject: [PATCH 1049/1085] vc4/hdmi: Ignore hotplug interrupt with force_hotplug The intention of the vc4.force_hotplug setting is to ignore hotplug completely. It can be used when a display toggles hotplug when switching AV inputs, going into standby or changing a KVM switch, and some side effect of that is unwanted. It turns out while vc4.force_hotplug currently makes hotplug always read as asserted, that isn't enough to stop drm doing lots of stuff, including re-reading the edid. An example of what drm does with a hotplug deasert/assert and vc4.force_hotplug=1 currently is: https://paste.debian.net/hidden/dc07434b/ That is unwanted. Lets ignore the hotplug interrupt completely so drm is blissfully unaware of the hotplug change. Signed-off-by: Dom Cobley --- drivers/gpu/drm/vc4/vc4_hdmi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -2923,7 +2923,7 @@ static irqreturn_t vc4_hdmi_hpd_irq_thre struct drm_connector *connector = &vc4_hdmi->connector; struct drm_device *dev = connector->dev; - if (dev && dev->registered) + if (dev && dev->registered && !force_hotplug) drm_connector_helper_hpd_irq_event(connector); return IRQ_HANDLED;