Commit 657a091a authored by Johan Hovold's avatar Johan Hovold Committed by Patrik Jakobsson
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drm/gma500/oaktrail_lvds: fix hang on init failure 



The LVDS init code looks up an I2C adapter using i2c_get_adapter() and
tries to read the EDID before falling back to allocating and registering
its own adapter.

The error handling does not separate these cases so on a late init
failure it will try to deregister and free also an adapter that had
previously been registered. Since i2c_get_adapter() takes another
reference to the adapter, deregistration hangs indefinitely while
waiting for the reference to be released.

Fix this by only destroying adapters allocated during LVDS init on
errors.

Fixes: a57ebfc0 ("drm/gma500: Make oaktrail lvds use ddc adapter from drm_connector")
Cc: stable@vger.kernel.org	# 6.0
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarPatrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patch.msgid.link/20260508144446.59722-3-johan@kernel.org
parent 950953f7

drivers/gpu/drm/gma500/oaktrail_lvds.c

+3 −2
Original line number Diff line number Diff line
@@ -293,7 +293,7 @@ void oaktrail_lvds_init(struct drm_device *dev, 
{

	struct gma_encoder *gma_encoder;

	struct gma_connector *gma_connector;

	struct gma_i2c_chan *ddc_bus;

	struct gma_i2c_chan *ddc_bus = NULL;

	struct drm_connector *connector;

	struct drm_encoder *encoder;

	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
@@ -421,7 +421,8 @@ void oaktrail_lvds_init(struct drm_device *dev, 


err_unlock:

	mutex_unlock(&dev->mode_config.mutex);

	gma_i2c_destroy(to_gma_i2c_chan(connector->ddc));

	if (!IS_ERR_OR_NULL(ddc_bus))

		gma_i2c_destroy(ddc_bus);

	drm_encoder_cleanup(encoder);

err_connector_cleanup:

	drm_connector_cleanup(connector);