[PATCH v5 02/10] drm/vc4: hdmi: Fix HPD GPIO detection

From: Maxime Ripard
Date: Mon Jun 28 2021 - 08:43:15 EST


Prior to commit 6800234ceee0 ("drm/vc4: hdmi: Convert to gpiod"), in the
detect hook, if we had an HPD GPIO we would only rely on it and return
whatever state it was in.

However, that commit changed that by mistake to only consider the case
where we have a GPIO and it returns a logical high, and would fall back
to the other methods otherwise.

Since we can read the EDIDs when the HPD signal is low on some displays,
we changed the detection status from disconnected to connected, and we
would ignore an HPD pulse.

Fixes: 6800234ceee0 ("drm/vc4: hdmi: Convert to gpiod")
Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index b8b371abf3d7..e7fdda8a1bfa 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -167,9 +167,9 @@ 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 &&
- gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio)) {
- connected = true;
+ if (vc4_hdmi->hpd_gpio) {
+ if (gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio))
+ connected = true;
} else if (HDMI_READ(HDMI_HOTPLUG) & VC4_HDMI_HOTPLUG_CONNECTED) {
connected = true;
}
--
2.31.1