[PATCH 6.6 141/299] drm/meson: Dont remove bridges which are created by other drivers

Greg Kroah-Hartman
2024-02-27T13:53:14Z

From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

commit bd915ae73a2d78559b376ad2caf5e4ef51de2455 upstream.

Stop calling drm_bridge_remove() for bridges allocated/managed by other
drivers in the remove paths of meson_encoder_{cvbs,dsi,hdmi}.
drm_bridge_remove() unregisters the bridge so it cannot be used
anymore. Doing so for bridges we don't own can lead to the video
pipeline not being able to come up after -EPROBE_DEFER of the VPU
because we're unregistering a bridge that's managed by another driver.
The other driver doesn't know that we have unregistered it's bridge
and on subsequent .probe() we're not able to find those bridges anymore
(since nobody re-creates them).

This fixes probe errors on Meson8b boards with the CVBS outputs enabled.

Fixes: 09847723c12f ("drm/meson: remove drm bridges at aggregate driver unbind time")
Fixes: 42dcf15f901c ("drm/meson: add DSI encoder")
Cc: <stable@vger.kernel.org>
Reported-by: Steve Morvai <stevemorvai@hotmail.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Tested-by: Steve Morvai <stevemorvai@hotmail.com>
Link: https://lore.kernel.org/r/20240215220442.1343152-1-martin.blumenstingl@googlemail.com
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240215220442.1343152-1-martin.blumenstingl@googlemail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/meson/meson_encoder_cvbs.c | 1 -
drivers/gpu/drm/meson/meson_encoder_dsi.c | 1 -
drivers/gpu/drm/meson/meson_encoder_hdmi.c | 1 -
3 files changed, 3 deletions(-)

--- a/drivers/gpu/drm/meson/meson_encoder_cvbs.c
+++ b/drivers/gpu/drm/meson/meson_encoder_cvbs.c
@@ -294,6 +294,5 @@ void meson_encoder_cvbs_remove(struct me
if (priv->encoders[MESON_ENC_CVBS]) {
meson_encoder_cvbs = priv->encoders[MESON_ENC_CVBS];
drm_bridge_remove(&meson_encoder_cvbs->bridge);
- drm_bridge_remove(meson_encoder_cvbs->next_bridge);
}
}
--- a/drivers/gpu/drm/meson/meson_encoder_dsi.c
+++ b/drivers/gpu/drm/meson/meson_encoder_dsi.c
@@ -168,6 +168,5 @@ void meson_encoder_dsi_remove(struct mes
if (priv->encoders[MESON_ENC_DSI]) {
meson_encoder_dsi = priv->encoders[MESON_ENC_DSI];
drm_bridge_remove(&meson_encoder_dsi->bridge);
- drm_bridge_remove(meson_encoder_dsi->next_bridge);
}
}
--- a/drivers/gpu/drm/meson/meson_encoder_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_encoder_hdmi.c
@@ -474,6 +474,5 @@ void meson_encoder_hdmi_remove(struct me
if (priv->encoders[MESON_ENC_HDMI]) {
meson_encoder_hdmi = priv->encoders[MESON_ENC_HDMI];
drm_bridge_remove(&meson_encoder_hdmi->bridge);
- drm_bridge_remove(meson_encoder_hdmi->next_bridge);
}
}