linux/include/drm/bridge/aux-bridge.h
Johan Hovold e5ca263508 drm/bridge: aux-hpd: separate allocation and registration
Combining allocation and registration is an anti-pattern that should be
avoided. Add two new functions for allocating and registering an dp-hpd
bridge with a proper 'devm' prefix so that it is clear that these are
device managed interfaces.

	devm_drm_dp_hpd_bridge_alloc()
	devm_drm_dp_hpd_bridge_add()

The new interface will be used to fix a use-after-free bug in the
Qualcomm PMIC GLINK driver and may prevent similar issues from being
introduced elsewhere.

The existing drm_dp_hpd_bridge_register() is reimplemented using the
above and left in place for now.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240217150228.5788-3-johan+linaro@kernel.org
2024-02-23 17:00:56 +02:00

53 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2023 Linaro Ltd.
*
* Author: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
*/
#ifndef DRM_AUX_BRIDGE_H
#define DRM_AUX_BRIDGE_H
#include <drm/drm_connector.h>
struct auxiliary_device;
#if IS_ENABLED(CONFIG_DRM_AUX_BRIDGE)
int drm_aux_bridge_register(struct device *parent);
#else
static inline int drm_aux_bridge_register(struct device *parent)
{
return 0;
}
#endif
#if IS_ENABLED(CONFIG_DRM_AUX_HPD_BRIDGE)
struct auxiliary_device *devm_drm_dp_hpd_bridge_alloc(struct device *parent, struct device_node *np);
int devm_drm_dp_hpd_bridge_add(struct device *dev, struct auxiliary_device *adev);
struct device *drm_dp_hpd_bridge_register(struct device *parent,
struct device_node *np);
void drm_aux_hpd_bridge_notify(struct device *dev, enum drm_connector_status status);
#else
static inline struct auxiliary_device *devm_drm_dp_hpd_bridge_alloc(struct device *parent,
struct device_node *np)
{
return NULL;
}
static inline int devm_drm_dp_hpd_bridge_add(struct auxiliary_device *adev)
{
return 0;
}
static inline struct device *drm_dp_hpd_bridge_register(struct device *parent,
struct device_node *np)
{
return NULL;
}
static inline void drm_aux_hpd_bridge_notify(struct device *dev, enum drm_connector_status status)
{
}
#endif
#endif