drm/gma500/oaktrail_lvds: fix i2c adapter leaks on init

commit 84d1c9b416d54afe760ca4c378bd95c89261254c upstream.

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.

Make sure to drop the references taken by i2c_get_adapter() when falling
back to allocating an adapter as well as on late errors to allow the
looked up adapter to be deregistered.

Fixes: 1b082cc ("gma500: Add Oaktrail support")
Cc: stable@vger.kernel.org	# 3.3
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patch.msgid.link/20260508144446.59722-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: jhovold

drivers/gpu/drm/gma500/oaktrail_lvds.c

@@ -366,6 +366,8 @@ void oaktrail_lvds_init(struct drm_device *dev,
 	if (edid == NULL && dev_priv->lpc_gpio_base) {
 		ddc_bus = oaktrail_lvds_i2c_init(dev);
 		if (!IS_ERR(ddc_bus)) {
+			if (i2c_adap)
+				i2c_put_adapter(i2c_adap);
 			i2c_adap = &ddc_bus->base;
 			edid = drm_get_edid(connector, i2c_adap);
 		}
@@ -422,6 +424,8 @@ void oaktrail_lvds_init(struct drm_device *dev,
 	mutex_unlock(&dev->mode_config.mutex);
 	if (!IS_ERR_OR_NULL(ddc_bus))
 		gma_i2c_destroy(ddc_bus);
+	else if (i2c_adap)
+		i2c_put_adapter(i2c_adap);
 	drm_encoder_cleanup(encoder);
 err_connector_cleanup:
 	drm_connector_cleanup(connector);