linux-kernel - [PATCH v2 05/15] drm/vc4: hdmi: Restore cec physical address on reconnect

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Date:   Mon, 11 Jan 2021 15:22:59 +0100
From:   Maxime Ripard <maxime@...no.tech>
To:     Eric Anholt <eric@...olt.net>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Maxime Ripard <maxime@...no.tech>,
        Daniel Vetter <daniel.vetter@...el.com>,
        David Airlie <airlied@...ux.ie>
Cc:     linux-rpi-kernel@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org,
        Hans Verkuil <hverkuil-cisco@...all.nl>,
        linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        bcm-kernel-feedback-list@...adcom.com,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Dave Stevenson <dave.stevenson@...pberrypi.com>,
        linux-media@...r.kernel.org, Dom Cobley <popcornmix@...il.com>
Subject: [PATCH v2 05/15] drm/vc4: hdmi: Restore cec physical address on reconnect

From: Dom Cobley <popcornmix@...il.com>

Currently we call cec_phys_addr_invalidate on a hotplug deassert.
That may be due to a TV power cycling, or an AVR being switched
on (and switching edid).

This makes CEC unusable since our controller wouldn't have a physical
address anymore.

Set it back up again on the hotplug assert.

Fixes: 15b4511a4af6 ("drm/vc4: add HDMI CEC support")
Signed-off-by: Dom Cobley <popcornmix@...il.com>
Signed-off-by: Maxime Ripard <maxime@...no.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 7945dbcee78c..c3a301396aad 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -136,20 +136,32 @@ static enum drm_connector_status
 vc4_hdmi_connector_detect(struct drm_connector *connector, bool force)
 {
 	struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector);
+	bool connected = false;
 
 	if (vc4_hdmi->hpd_gpio) {
 		if (gpio_get_value_cansleep(vc4_hdmi->hpd_gpio) ^
 		    vc4_hdmi->hpd_active_low)
-			return connector_status_connected;
-		cec_phys_addr_invalidate(vc4_hdmi->cec_adap);
-		return connector_status_disconnected;
+			connected = true;
+	} else if (drm_probe_ddc(vc4_hdmi->ddc)) {
+		connected = true;
+	} else if (HDMI_READ(HDMI_HOTPLUG) & VC4_HDMI_HOTPLUG_CONNECTED) {
+		connected = true;
 	}
 
-	if (drm_probe_ddc(vc4_hdmi->ddc))
-		return connector_status_connected;
+	if (connected) {
+		if (connector->status != connector_status_connected) {
+			struct edid *edid = drm_get_edid(connector, vc4_hdmi->ddc);
+
+			if (edid) {
+				cec_s_phys_addr_from_edid(vc4_hdmi->cec_adap, edid);
+				vc4_hdmi->encoder.hdmi_monitor = drm_detect_hdmi_monitor(edid);
+				kfree(edid);
+			}
+		}
 
-	if (HDMI_READ(HDMI_HOTPLUG) & VC4_HDMI_HOTPLUG_CONNECTED)
 		return connector_status_connected;
+	}
+
 	cec_phys_addr_invalidate(vc4_hdmi->cec_adap);
 	return connector_status_disconnected;
 }
-- 
2.29.2