| Message ID | 20180414115318.14500-24-noralf@tronnes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
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);
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> --- drivers/gpu/drm/drm_drv.c | 32 ++++++++++++++++++++++++++++++++ include/drm/drm_drv.h | 4 ++++ 2 files changed, 36 insertions(+)