Commit 6aed8ec3 authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm: review locking for drm_fb_helper_restore_fbdev_mode 



... it's required. Fix up exynos and the cma helper, and add a
corresponding WARN_ON to drm_fb_helper_restore_fbdev_mode.

Note that tegra calls the fbdev cma helper restore function also from
it's driver-load callback. Which is a bit against current practice,
since usually the call is only from ->lastclose, and initial setup is
done by drm_fb_helper_initial_config.

Also add the relevant drm DocBook entry.

v2: Add promised WARN to restore_fbdev_mode.

Reviewed-by: default avatarRob Clark <robdclark@gmail.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent b9e50713

drivers/gpu/drm/drm_crtc.c

+15 −1
Original line number Diff line number Diff line
@@ -68,9 +68,23 @@ void drm_modeset_unlock_all(struct drm_device *dev) 


	mutex_unlock(&dev->mode_config.mutex);

}



EXPORT_SYMBOL(drm_modeset_unlock_all);



/**

 * drm_warn_on_modeset_not_all_locked - check that all modeset locks are locked

 * @dev: device

 */

void drm_warn_on_modeset_not_all_locked(struct drm_device *dev)

{

	struct drm_crtc *crtc;



	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)

		WARN_ON(!mutex_is_locked(&crtc->mutex));



	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));

}

EXPORT_SYMBOL(drm_warn_on_modeset_not_all_locked);



/* Avoid boilerplate.  I'm tired of typing. */

#define DRM_ENUM_NAME_FN(fnname, list)				\

	char *fnname(int val)					\

drivers/gpu/drm/drm_fb_cma_helper.c

+2 −0
Original line number Diff line number Diff line
@@ -389,8 +389,10 @@ EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini); 
 */

void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma)

{

	drm_modeset_lock_all(dev);

	if (fbdev_cma)

		drm_fb_helper_restore_fbdev_mode(&fbdev_cma->fb_helper);

	drm_modeset_unlock_all(dev);

}

EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);

drivers/gpu/drm/drm_fb_helper.c

+11 −0
Original line number Diff line number Diff line
@@ -239,10 +239,21 @@ int drm_fb_helper_debug_leave(struct fb_info *info) 
}

EXPORT_SYMBOL(drm_fb_helper_debug_leave);



/**

 * drm_fb_helper_restore_fbdev_mode - restore fbdev configuration

 * @fb_helper: fbcon to restore

 *

 * This should be called from driver's drm->lastclose callback when implementing

 * an fbcon on top of kms using this helper. This ensures that the user isn't

 * greeted with a black screen when e.g. X dies.

 */

bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)

{

	bool error = false;

	int i, ret;



	drm_warn_on_modeset_not_all_locked(fb_helper->dev);



	for (i = 0; i < fb_helper->crtc_count; i++) {

		struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;

		ret = drm_mode_set_config_internal(mode_set);

drivers/gpu/drm/exynos/exynos_drm_fbdev.c

+2 −0
Original line number Diff line number Diff line
@@ -376,5 +376,7 @@ void exynos_drm_fbdev_restore_mode(struct drm_device *dev) 
	if (!private || !private->fb_helper)

		return;



	drm_modeset_lock_all(dev);

	drm_fb_helper_restore_fbdev_mode(private->fb_helper);

	drm_modeset_unlock_all(dev);

}

include/drm/drm_crtc.h

+1 −0
Original line number Diff line number Diff line
@@ -867,6 +867,7 @@ struct drm_prop_enum_list { 


extern void drm_modeset_lock_all(struct drm_device *dev);

extern void drm_modeset_unlock_all(struct drm_device *dev);

extern void drm_warn_on_modeset_not_all_locked(struct drm_device *dev);



extern int drm_crtc_init(struct drm_device *dev,

			 struct drm_crtc *crtc,

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