We don't need to hold onto mode_config.mutex any more to keep the fb objects around. And locking dev->struct_mutex is also not required, since omap_gem_describe only reads data anyway. And for a debug interface it's better to grab fewer locks in case the driver is deadlocked already ...
The only thing we need is to hold onto mode_config.fb_lock to ensure the user-created fbs don't disappear. The fbcon fb doesn't need any protection, since it lives as long as the driver (and so the debugfs files) itself. And if the teardown/setup isn't following the right sequence grabbing locks won't prevent a NULL deref on priv->fbdev if the fb is not yet (or no longer) there.
Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/staging/omapdrm/omap_debugfs.c | 14 -------------- 1 file changed, 14 deletions(-)
diff --git a/drivers/staging/omapdrm/omap_debugfs.c b/drivers/staging/omapdrm/omap_debugfs.c index e95540b..2bf0664 100644 --- a/drivers/staging/omapdrm/omap_debugfs.c +++ b/drivers/staging/omapdrm/omap_debugfs.c @@ -57,17 +57,6 @@ static int fb_show(struct seq_file *m, void *arg) struct drm_device *dev = node->minor->dev; struct omap_drm_private *priv = dev->dev_private; struct drm_framebuffer *fb; - int ret; - - ret = mutex_lock_interruptible(&dev->mode_config.mutex); - if (ret) - return ret; - - ret = mutex_lock_interruptible(&dev->struct_mutex); - if (ret) { - mutex_unlock(&dev->mode_config.mutex); - return ret; - }
seq_printf(m, "fbcon "); omap_framebuffer_describe(priv->fbdev->fb, m); @@ -82,9 +71,6 @@ static int fb_show(struct seq_file *m, void *arg) } mutex_unlock(&dev->mode_config.fb_lock);
- mutex_unlock(&dev->struct_mutex); - mutex_unlock(&dev->mode_config.mutex); - return 0; }