mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-23 15:32:33 +00:00
48 lines
2.0 KiB
Diff
48 lines
2.0 KiB
Diff
|
From faa24f47c0066893e0b7772befe378bde4dc2ff9 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Maxime Ripard <maxime@cerno.tech>
|
||
|
|
Date: Mon, 25 Oct 2021 17:28:54 +0200
|
||
|
|
Subject: [PATCH] drm/vc4: hdmi: Remove the DDC probing for status
|
||
|
|
detection
|
||
|
|
|
||
|
|
Commit 9d44abbbb8d5 ("drm/vc4: Fall back to using an EDID probe in the
|
||
|
|
absence of a GPIO.") added some code to read the EDID through DDC in the
|
||
|
|
HDMI driver detect hook since the Pi3 had no HPD GPIO back then.
|
||
|
|
However, commit b1b8f45b3130 ("ARM: dts: bcm2837: Add missing GPIOs of
|
||
|
|
Expander") changed that a couple of years later.
|
||
|
|
|
||
|
|
This causes an issue though since some TV (like the LG 55C8) when it
|
||
|
|
comes out of standy will deassert the HPD line, but the EDID will
|
||
|
|
remain readable.
|
||
|
|
|
||
|
|
It causes an issues nn platforms without an HPD GPIO, like the Pi4,
|
||
|
|
where the DDC probing will be our primary mean to detect a display, and
|
||
|
|
thus we will never detect the HPD pulse. This was fine before since the
|
||
|
|
pulse was small enough that we would never detect it, and we also didn't
|
||
|
|
have anything (like the scrambler) that needed to be set up in the
|
||
|
|
display.
|
||
|
|
|
||
|
|
However, now that we have both, the display during the HPD pulse will
|
||
|
|
clear its scrambler status, and since we won't detect the
|
||
|
|
disconnect/reconnect cycle we will never enable the scrambler back.
|
||
|
|
|
||
|
|
As our main reason for that DDC probing is gone, let's just remove it.
|
||
|
|
|
||
|
|
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
|
||
|
|
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
|
||
|
|
Link: https://lore.kernel.org/r/20211025152903.1088803-2-maxime@cerno.tech
|
||
|
|
---
|
||
|
|
drivers/gpu/drm/vc4/vc4_hdmi.c | 2 --
|
||
|
|
1 file changed, 2 deletions(-)
|
||
|
|
|
||
|
|
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
|
||
|
|
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
|
||
|
|
@@ -175,8 +175,6 @@ vc4_hdmi_connector_detect(struct drm_con
|
||
|
|
if (vc4_hdmi->hpd_gpio &&
|
||
|
|
gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio)) {
|
||
|
|
connected = true;
|
||
|
|
- } else if (drm_probe_ddc(vc4_hdmi->ddc)) {
|
||
|
|
- connected = true;
|
||
|
|
} else if (HDMI_READ(HDMI_HOTPLUG) & VC4_HDMI_HOTPLUG_CONNECTED) {
|
||
|
|
connected = true;
|
||
|
|
}
|