linux/include/drm/drm_crtc_helper.h
Lukas Wunner 25c058ccaf drm: Allow determining if current task is output poll worker
Introduce a helper to determine if the current task is an output poll
worker.

This allows us to fix a long-standing deadlock in several DRM drivers
wherein the ->runtime_suspend callback waits for the output poll worker
to finish and the worker in turn calls a ->detect callback which waits
for runtime suspend to finish.  The ->detect callback is invoked from
multiple call sites and waiting for runtime suspend to finish is the
correct thing to do except if it's executing in the context of the
worker.

v2: Expand kerneldoc to specifically mention deadlock between
    output poll worker and autosuspend worker as use case. (Lyude)

Cc: Dave Airlie <airlied@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://patchwork.freedesktop.org/patch/msgid/3549ce32e7f1467102e70d3e9cbf70c46bfe108e.1518593424.git.lukas@wunner.de
2018-02-16 22:30:06 +01:00

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3.3 KiB
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/*
* Copyright © 2006 Keith Packard
* Copyright © 2007-2008 Dave Airlie
* Copyright © 2007-2008 Intel Corporation
* Jesse Barnes <jesse.barnes@intel.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
/*
* The DRM mode setting helper functions are common code for drivers to use if
* they wish. Drivers are not forced to use this code in their
* implementations but it would be useful if they code they do use at least
* provides a consistent interface and operation to userspace
*/
#ifndef __DRM_CRTC_HELPER_H__
#define __DRM_CRTC_HELPER_H__
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/idr.h>
#include <linux/fb.h>
#include <drm/drm_crtc.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_modeset_helper.h>
void drm_helper_disable_unused_functions(struct drm_device *dev);
int drm_crtc_helper_set_config(struct drm_mode_set *set,
struct drm_modeset_acquire_ctx *ctx);
bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
struct drm_display_mode *mode,
int x, int y,
struct drm_framebuffer *old_fb);
bool drm_helper_crtc_in_use(struct drm_crtc *crtc);
bool drm_helper_encoder_in_use(struct drm_encoder *encoder);
int drm_helper_connector_dpms(struct drm_connector *connector, int mode);
void drm_helper_resume_force_mode(struct drm_device *dev);
int drm_helper_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode,
struct drm_display_mode *adjusted_mode, int x, int y,
struct drm_framebuffer *old_fb);
int drm_helper_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
struct drm_framebuffer *old_fb);
/* drm_probe_helper.c */
int drm_helper_probe_single_connector_modes(struct drm_connector
*connector, uint32_t maxX,
uint32_t maxY);
int drm_helper_probe_detect(struct drm_connector *connector,
struct drm_modeset_acquire_ctx *ctx,
bool force);
void drm_kms_helper_poll_init(struct drm_device *dev);
void drm_kms_helper_poll_fini(struct drm_device *dev);
bool drm_helper_hpd_irq_event(struct drm_device *dev);
void drm_kms_helper_hotplug_event(struct drm_device *dev);
void drm_kms_helper_poll_disable(struct drm_device *dev);
void drm_kms_helper_poll_enable(struct drm_device *dev);
bool drm_kms_helper_is_poll_worker(void);
#endif