Commit dfe96ddc authored by Daniel Vetter's avatar Daniel Vetter Committed by Rob Clark

omapdrm: simplify locking in the fb debugfs file

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: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarRob Clark <robdclark@gmail.com>
parent 16ef3dfe
...@@ -57,17 +57,6 @@ static int fb_show(struct seq_file *m, void *arg) ...@@ -57,17 +57,6 @@ static int fb_show(struct seq_file *m, void *arg)
struct drm_device *dev = node->minor->dev; struct drm_device *dev = node->minor->dev;
struct omap_drm_private *priv = dev->dev_private; struct omap_drm_private *priv = dev->dev_private;
struct drm_framebuffer *fb; 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 "); seq_printf(m, "fbcon ");
omap_framebuffer_describe(priv->fbdev->fb, m); omap_framebuffer_describe(priv->fbdev->fb, m);
...@@ -82,9 +71,6 @@ static int fb_show(struct seq_file *m, void *arg) ...@@ -82,9 +71,6 @@ static int fb_show(struct seq_file *m, void *arg)
} }
mutex_unlock(&dev->mode_config.fb_lock); mutex_unlock(&dev->mode_config.fb_lock);
mutex_unlock(&dev->struct_mutex);
mutex_unlock(&dev->mode_config.mutex);
return 0; return 0;
} }
......
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