On Sat, Apr 14, 2018 at 01:53:16PM +0200, Noralf Trønnes wrote:
Add a notifier that fires when a new DRM device is registered. This can be used by the bootsplash client to connect to all devices.
Signed-off-by: Noralf Trønnes noralf@tronnes.org
So I freaked out temporarily about your usage of notifiers here. But I think this one of the few cases where using notifiers is actually perfectly fine. Still not sure we really want that, instead of just hard-coding calls to the various register functions directly (and using a dummy no-op replacement if that part isn't enabled in Kconfig). -Daniel
drivers/gpu/drm/drm_drv.c | 32 ++++++++++++++++++++++++++++++++ include/drm/drm_drv.h | 4 ++++ 2 files changed, 36 insertions(+)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 6f21bafb29be..e42ce320ad07 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -31,6 +31,7 @@ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/mount.h> +#include <linux/notifier.h> #include <linux/slab.h> #include <linux/srcu.h>
@@ -79,6 +80,8 @@ static struct dentry *drm_debugfs_root;
DEFINE_STATIC_SRCU(drm_unplug_srcu);
+static BLOCKING_NOTIFIER_HEAD(drm_dev_notifier);
/*
- DRM Minors
- A DRM device can provide several char-dev interfaces on the DRM-Major. Each
@@ -837,6 +840,8 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags) dev->dev ? dev_name(dev->dev) : "virtual device", dev->primary->index);
- blocking_notifier_call_chain(&drm_dev_notifier, 0, dev);
- goto out_unlock;
err_minors: @@ -894,6 +899,33 @@ void drm_dev_unregister(struct drm_device *dev) } EXPORT_SYMBOL(drm_dev_unregister);
+/**
- drm_dev_register_notifier - Register a notifier for new DRM devices
- @nb: Notifier block
- Register a notifier that fires when a new &drm_device is registered.
- Note:
- Users of this function has to be linked into drm.ko. This is done to make
- life simple avoiding tricky race situations.
- */
+void drm_dev_register_notifier(struct notifier_block *nb) +{
- /* Currently this can't fail, but catch it in case this changes */
- WARN_ON(blocking_notifier_chain_register(&drm_dev_notifier, nb));
+}
+/**
- drm_dev_unregister_notifier - Unregister DRM device notifier
- @nb: Notifier block
- This is a no-op if the notifier isn't registered.
- */
+void drm_dev_unregister_notifier(struct notifier_block *nb) +{
- blocking_notifier_chain_unregister(&drm_dev_notifier, nb);
+}
/**
- drm_dev_set_unique - Set the unique name of a DRM device
- @dev: device of which to set the unique name
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h index 13356e6fd40c..5e6c6ed0d59d 100644 --- a/include/drm/drm_drv.h +++ b/include/drm/drm_drv.h @@ -40,6 +40,7 @@ struct drm_minor; struct dma_buf_attachment; struct drm_display_mode; struct drm_mode_create_dumb; +struct notifier_block; struct drm_printer;
/* driver capabilities and requirements mask */ @@ -641,6 +642,9 @@ struct drm_device *drm_dev_alloc(struct drm_driver *driver, int drm_dev_register(struct drm_device *dev, unsigned long flags); void drm_dev_unregister(struct drm_device *dev);
+void drm_dev_register_notifier(struct notifier_block *nb); +void drm_dev_unregister_notifier(struct notifier_block *nb);
void drm_dev_get(struct drm_device *dev); void drm_dev_put(struct drm_device *dev); void drm_dev_unref(struct drm_device *dev); -- 2.15.1
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