diff options
| -rw-r--r-- | drivers/gpu/drm/drm_drv.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index f74b7d06ec01..a525751b4559 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -647,6 +647,62 @@ void drm_dev_unref(struct drm_device *dev) } EXPORT_SYMBOL(drm_dev_unref); +static int create_compat_control_link(struct drm_device *dev) +{ + struct drm_minor *minor; + char *name; + int ret; + + if (!drm_core_check_feature(dev, DRIVER_MODESET)) + return 0; + + minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY); + if (!minor) + return 0; + + /* + * Some existing userspace out there uses the existing of the controlD* + * sysfs files to figure out whether it's a modeset driver. It only does + * readdir, hence a symlink is sufficient (and the least confusing + * option). Otherwise controlD* is entirely unused. + * + * Old controlD chardev have been allocated in the range + * 64-127. + */ + name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64); + if (!name) + return -ENOMEM; + + ret = sysfs_create_link(minor->kdev->kobj.parent, + &minor->kdev->kobj, + name); + + kfree(name); + + return ret; +} + +static void remove_compat_control_link(struct drm_device *dev) +{ + struct drm_minor *minor; + char *name; + + if (!drm_core_check_feature(dev, DRIVER_MODESET)) + return; + + minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY); + if (!minor) + return; + + name = kasprintf(GFP_KERNEL, "controlD%d", minor->index); + if (!name) + return; + + sysfs_remove_link(minor->kdev->kobj.parent, name); + + kfree(name); +} + /** * drm_dev_register - Register DRM device * @dev: Device to register @@ -685,6 +741,10 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags) if (ret) goto err_minors; + ret = create_compat_control_link(dev); + if (ret) + goto err_minors; + if (dev->driver->load) { ret = dev->driver->load(dev, flags); if (ret) @@ -698,6 +758,7 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags) goto out_unlock; err_minors: + remove_compat_control_link(dev); drm_minor_unregister(dev, DRM_MINOR_PRIMARY); drm_minor_unregister(dev, DRM_MINOR_RENDER); drm_minor_unregister(dev, DRM_MINOR_CONTROL); @@ -738,6 +799,7 @@ void drm_dev_unregister(struct drm_device *dev) list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) drm_legacy_rmmap(dev, r_list->map); + remove_compat_control_link(dev); drm_minor_unregister(dev, DRM_MINOR_PRIMARY); drm_minor_unregister(dev, DRM_MINOR_RENDER); drm_minor_unregister(dev, DRM_MINOR_CONTROL); |