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authorDave Airlie <airlied@redhat.com>2016-12-13 07:24:25 +0300
committerDave Airlie <airlied@redhat.com>2016-12-13 07:24:25 +0300
commit8a5c61f4ffa56cf85e21bfa5777440d4a736ef7d (patch)
tree2ade2d62339e6affa67b1555d641fd01b2cf6291 /drivers
parent2601a15d5d9b7f262e94b88784b1e1cf28ec020d (diff)
parent6449b088dd51dd5aa6b38455888bbf538d21f2fc (diff)
downloadlinux-8a5c61f4ffa56cf85e21bfa5777440d4a736ef7d.tar.xz
Merge tag 'drm-misc-next-fixes-2016-12-10' of git://anongit.freedesktop.org/git/drm-misc into drm-next
single fix for backwards compat. * tag 'drm-misc-next-fixes-2016-12-10' of git://anongit.freedesktop.org/git/drm-misc: drm: Add fake controlD* symlinks for backwards compat
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/drm_drv.c62
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);