Commit e1728075 authored by David Herrmann's avatar David Herrmann

drm: make sysfs device always available for minors

For each minor we allocate a sysfs device as minor->kdev. Currently, this
is allocated and registered in drm_minor_register(). This makes it
impossible to add sysfs-attributes to the device before it is registered.
Therefore, they are not added atomically, nor can we move device_add()
*after* ->load() is called.

This patch makes minor->kdev available early, but only adds the device
during minor-registration. Note that the registration is still called
before ->load() as debugfs needs to be split, too. This will be fixed in
follow-ups.
Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
parent f1b85962
......@@ -281,9 +281,19 @@ static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
minor->index = r;
minor->kdev = drm_sysfs_minor_alloc(minor);
if (IS_ERR(minor->kdev)) {
r = PTR_ERR(minor->kdev);
goto err_index;
}
*drm_minor_get_slot(dev, type) = minor;
return 0;
err_index:
spin_lock_irqsave(&drm_minor_lock, flags);
idr_remove(&drm_minors_idr, minor->index);
spin_unlock_irqrestore(&drm_minor_lock, flags);
err_free:
kfree(minor);
return r;
......@@ -300,6 +310,7 @@ static void drm_minor_free(struct drm_device *dev, unsigned int type)
return;
drm_mode_group_destroy(&minor->mode_group);
put_device(minor->kdev);
spin_lock_irqsave(&drm_minor_lock, flags);
idr_remove(&drm_minors_idr, minor->index);
......@@ -327,11 +338,9 @@ static int drm_minor_register(struct drm_device *dev, unsigned int type)
return ret;
}
ret = drm_sysfs_device_add(minor);
if (ret) {
DRM_ERROR("DRM: Error sysfs_device_add.\n");
ret = device_add(minor->kdev);
if (ret)
goto err_debugfs;
}
/* replace NULL with @minor so lookups will succeed from now on */
spin_lock_irqsave(&drm_minor_lock, flags);
......@@ -352,7 +361,7 @@ static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
unsigned long flags;
minor = *drm_minor_get_slot(dev, type);
if (!minor || !minor->kdev)
if (!minor || !device_is_registered(minor->kdev))
return;
/* replace @minor with NULL so lookups will fail from now on */
......@@ -360,8 +369,9 @@ static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
idr_replace(&drm_minors_idr, NULL, minor->index);
spin_unlock_irqrestore(&drm_minor_lock, flags);
device_del(minor->kdev);
dev_set_drvdata(minor->kdev, NULL); /* safety belt */
drm_debugfs_cleanup(minor);
drm_sysfs_device_remove(minor);
}
/**
......
......@@ -493,17 +493,23 @@ static void drm_sysfs_release(struct device *dev)
}
/**
* drm_sysfs_device_add - adds a class device to sysfs for a character driver
* @dev: DRM device to be added
* @head: DRM head in question
* drm_sysfs_minor_alloc() - Allocate sysfs device for given minor
* @minor: minor to allocate sysfs device for
*
* Add a DRM device to the DRM's device model class. We use @dev's PCI device
* as the parent for the Linux device, and make sure it has a file containing
* the driver we're using (for userspace compatibility).
* This allocates a new sysfs device for @minor and returns it. The device is
* not registered nor linked. The caller has to use device_add() and
* device_del() to register and unregister it.
*
* Note that dev_get_drvdata() on the new device will return the minor.
* However, the device does not hold a ref-count to the minor nor to the
* underlying drm_device. This is unproblematic as long as you access the
* private data only in sysfs callbacks. device_del() disables those
* synchronously, so they cannot be called after you cleanup a minor.
*/
int drm_sysfs_device_add(struct drm_minor *minor)
struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
{
char *minor_str;
const char *minor_str;
struct device *kdev;
int r;
if (minor->type == DRM_MINOR_CONTROL)
......@@ -513,51 +519,29 @@ int drm_sysfs_device_add(struct drm_minor *minor)
else
minor_str = "card%d";
minor->kdev = kzalloc(sizeof(*minor->kdev), GFP_KERNEL);
if (!minor->kdev) {
r = -ENOMEM;
goto error;
}
device_initialize(minor->kdev);
minor->kdev->devt = MKDEV(DRM_MAJOR, minor->index);
minor->kdev->class = drm_class;
minor->kdev->type = &drm_sysfs_device_minor;
minor->kdev->parent = minor->dev->dev;
minor->kdev->release = drm_sysfs_release;
dev_set_drvdata(minor->kdev, minor);
kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
if (!kdev)
return ERR_PTR(-ENOMEM);
r = dev_set_name(minor->kdev, minor_str, minor->index);
if (r < 0)
goto error;
device_initialize(kdev);
kdev->devt = MKDEV(DRM_MAJOR, minor->index);
kdev->class = drm_class;
kdev->type = &drm_sysfs_device_minor;
kdev->parent = minor->dev->dev;
kdev->release = drm_sysfs_release;
dev_set_drvdata(kdev, minor);
r = device_add(minor->kdev);
r = dev_set_name(kdev, minor_str, minor->index);
if (r < 0)
goto error;
return 0;
goto err_free;
error:
DRM_ERROR("device create failed %d\n", r);
put_device(minor->kdev);
return r;
}
return kdev;
/**
* drm_sysfs_device_remove - remove DRM device
* @dev: DRM device to remove
*
* This call unregisters and cleans up a class device that was created with a
* call to drm_sysfs_device_add()
*/
void drm_sysfs_device_remove(struct drm_minor *minor)
{
if (minor->kdev)
device_unregister(minor->kdev);
minor->kdev = NULL;
err_free:
put_device(kdev);
return ERR_PTR(r);
}
/**
* drm_class_device_register - Register a struct device in the drm class.
*
......
......@@ -1502,9 +1502,8 @@ extern int drm_pci_set_unique(struct drm_device *dev,
struct drm_sysfs_class;
extern struct class *drm_sysfs_create(struct module *owner, char *name);
extern void drm_sysfs_destroy(void);
extern int drm_sysfs_device_add(struct drm_minor *minor);
extern struct device *drm_sysfs_minor_alloc(struct drm_minor *minor);
extern void drm_sysfs_hotplug_event(struct drm_device *dev);
extern void drm_sysfs_device_remove(struct drm_minor *minor);
extern int drm_sysfs_connector_add(struct drm_connector *connector);
extern void drm_sysfs_connector_remove(struct drm_connector *connector);
......
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