drm/vkms: Use drmm_add_final_kfree

With this we can drop the final kfree from the release function.

v2: After drm_dev_init/drmm_add_final_kfree we need to clean up
everything through a drm_dev_put. Rework the unwind code to match
that.
Reviewed-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Tested-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: Haneen Mohammed <hamohammed.sa@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-15-daniel.vetter@ffwll.ch

drivers/gpu/drm/vkms/vkms_drv.c

@@ -21,6 +21,7 @@
 #include <drm/drm_file.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_ioctl.h>
+#include <drm/drm_managed.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
 
@@ -158,13 +159,14 @@ static int __init vkms_init(void)
 			   &vkms_device->platform->dev);
 	if (ret)
 		goto out_unregister;
+	drmm_add_final_kfree(&vkms_device->drm, vkms_device);
 
 	ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
 					   DMA_BIT_MASK(64));
 
 	if (ret) {
 		DRM_ERROR("Could not initialize DMA support\n");
-		goto out_fini;
+		goto out_put;
 	}
 
 	vkms_device->drm.irq_enabled = true;
@@ -172,25 +174,25 @@ static int __init vkms_init(void)
 	ret = drm_vblank_init(&vkms_device->drm, 1);
 	if (ret) {
 		DRM_ERROR("Failed to vblank\n");
-		goto out_fini;
+		goto out_put;
 	}
 
 	ret = vkms_modeset_init(vkms_device);
 	if (ret)
-		goto out_fini;
+		goto out_put;
 
 	ret = drm_dev_register(&vkms_device->drm, 0);
 	if (ret)
-		goto out_fini;
+		goto out_put;
 
 	return 0;
 
-out_fini:
-	drm_dev_fini(&vkms_device->drm);
+out_put:
+	drm_dev_put(&vkms_device->drm);
+	return ret;
 
 out_unregister:
 	platform_device_unregister(vkms_device->platform);
-
 out_free:
 	kfree(vkms_device);
 	return ret;
@@ -205,8 +207,6 @@ static void __exit vkms_exit(void)
 
 	drm_dev_unregister(&vkms_device->drm);
 	drm_dev_put(&vkms_device->drm);
-
-	kfree(vkms_device);
 }
 
 module_init(vkms_init);