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: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Daniel Vetter 2013-01-20 17:32:21 +01:00
parent b9e5071386
commit 6aed8ec3f7
5 changed files with 31 additions and 1 deletions

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@ -68,9 +68,23 @@ void drm_modeset_unlock_all(struct drm_device *dev)
mutex_unlock(&dev->mode_config.mutex); mutex_unlock(&dev->mode_config.mutex);
} }
EXPORT_SYMBOL(drm_modeset_unlock_all); 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. */ /* Avoid boilerplate. I'm tired of typing. */
#define DRM_ENUM_NAME_FN(fnname, list) \ #define DRM_ENUM_NAME_FN(fnname, list) \
char *fnname(int val) \ char *fnname(int val) \

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@ -389,8 +389,10 @@ EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);
*/ */
void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma) void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma)
{ {
drm_modeset_lock_all(dev);
if (fbdev_cma) if (fbdev_cma)
drm_fb_helper_restore_fbdev_mode(&fbdev_cma->fb_helper); drm_fb_helper_restore_fbdev_mode(&fbdev_cma->fb_helper);
drm_modeset_unlock_all(dev);
} }
EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode); EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);

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@ -239,10 +239,21 @@ int drm_fb_helper_debug_leave(struct fb_info *info)
} }
EXPORT_SYMBOL(drm_fb_helper_debug_leave); 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 drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)
{ {
bool error = false; bool error = false;
int i, ret; int i, ret;
drm_warn_on_modeset_not_all_locked(fb_helper->dev);
for (i = 0; i < fb_helper->crtc_count; i++) { for (i = 0; i < fb_helper->crtc_count; i++) {
struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set; struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
ret = drm_mode_set_config_internal(mode_set); ret = drm_mode_set_config_internal(mode_set);

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@ -376,5 +376,7 @@ void exynos_drm_fbdev_restore_mode(struct drm_device *dev)
if (!private || !private->fb_helper) if (!private || !private->fb_helper)
return; return;
drm_modeset_lock_all(dev);
drm_fb_helper_restore_fbdev_mode(private->fb_helper); drm_fb_helper_restore_fbdev_mode(private->fb_helper);
drm_modeset_unlock_all(dev);
} }

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@ -867,6 +867,7 @@ struct drm_prop_enum_list {
extern void drm_modeset_lock_all(struct drm_device *dev); extern void drm_modeset_lock_all(struct drm_device *dev);
extern void drm_modeset_unlock_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, extern int drm_crtc_init(struct drm_device *dev,
struct drm_crtc *crtc, struct drm_crtc *crtc,