If struct fb_ops is defined in a library like cma, fb_open() and fbcon takes a ref on the library instead of the driver module. Use fb_ops.fb_open/fb_release to ensure that the driver module is pinned.
Add drm_fb_helper_fb_open() and drm_fb_helper_fb_release() to DRM_FB_HELPER_DEFAULT_OPS().
Signed-off-by: Noralf Trønnes noralf@tronnes.org --- drivers/gpu/drm/drm_fb_helper.c | 40 ++++++++++++++++++++++++++++++++++++++++ include/drm/drm_fb_helper.h | 15 +++++++++++++++ 2 files changed, 55 insertions(+)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 035784ddd133..2c6adf1d80c2 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1207,6 +1207,46 @@ void drm_fb_helper_cfb_imageblit(struct fb_info *info, } EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
+/** + * drm_fb_helper_fb_open - implementation for &fb_ops.fb_open + * @info: fbdev registered by the helper + * @user: 1=userspace, 0=fbcon + * + * If &fb_ops is wrapped in a library, pin the driver module. + */ +int drm_fb_helper_fb_open(struct fb_info *info, int user) +{ + struct drm_fb_helper *fb_helper = info->par; + struct drm_device *dev = fb_helper->dev; + + if (info->fbops->owner != dev->driver->fops->owner) { + if (!try_module_get(dev->driver->fops->owner)) + return -ENODEV; + } + + return 0; +} +EXPORT_SYMBOL(drm_fb_helper_fb_open); + +/** + * drm_fb_helper_fb_release - implementation for &fb_ops.fb_release + * @info: fbdev registered by the helper + * @user: 1=userspace, 0=fbcon + * + * If &fb_ops is wrapped in a library, unpin the driver module. + */ +int drm_fb_helper_fb_release(struct fb_info *info, int user) +{ + struct drm_fb_helper *fb_helper = info->par; + struct drm_device *dev = fb_helper->dev; + + if (info->fbops->owner != dev->driver->fops->owner) + module_put(dev->driver->fops->owner); + + return 0; +} +EXPORT_SYMBOL(drm_fb_helper_fb_release); + /** * drm_fb_helper_set_suspend - wrapper around fb_set_suspend * @fb_helper: driver-allocated fbdev helper, can be NULL diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h index b069433e7fc1..6f546ca3a6a1 100644 --- a/include/drm/drm_fb_helper.h +++ b/include/drm/drm_fb_helper.h @@ -241,6 +241,8 @@ struct drm_fb_helper { * functions. To be used in struct fb_ops of drm drivers. */ #define DRM_FB_HELPER_DEFAULT_OPS \ + .fb_open = drm_fb_helper_fb_open, \ + .fb_release = drm_fb_helper_fb_release, \ .fb_check_var = drm_fb_helper_check_var, \ .fb_set_par = drm_fb_helper_set_par, \ .fb_setcmap = drm_fb_helper_setcmap, \ @@ -297,6 +299,9 @@ void drm_fb_helper_cfb_copyarea(struct fb_info *info, void drm_fb_helper_cfb_imageblit(struct fb_info *info, const struct fb_image *image);
+int drm_fb_helper_fb_open(struct fb_info *info, int user); +int drm_fb_helper_fb_release(struct fb_info *info, int user); + void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend); void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend); @@ -473,6 +478,16 @@ static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info, { }
+static inline int drm_fb_helper_fb_open(struct fb_info *info, int user) +{ + return -ENODEV; +} + +static inline int drm_fb_helper_fb_release(struct fb_info *info, int user) +{ + return -ENODEV; +} + static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend) {