drm/fb-helper: Allocate and release fb_info in single place

Move the calls to drm_fb_helper_alloc_info() from drivers into a
single place in fbdev helpers. Allocates struct fb_info for a new
framebuffer device. Then call drm_fb_helper_single_fb_probe() to
create an fbdev screen buffer. Also release the instance on errors
by calling drm_fb_helper_release_info().

Simplifies the code and fixes the error cleanup for some of the
drivers.

Regular release of the struct fb_info instance still happens in
drm_fb_helper_fini() as before.

v2:
- remove error rollback in driver implementations (kernel test robot)
- initialize info in TTM implementation (kernel test robot)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Christian König <christian.koenig@amd.com> # radeon
Acked-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> # msm
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patch.msgid.link/20251027081245.80262-1-tzimmermann@suse.de

1 files changed, 1 insertions, 11 deletions

diff --git a/drivers/gpu/drm/gma500/fbdev.c b/drivers/gpu/drm/gma500/fbdev.c
index bc92fa24a1e2..c26926babc2a 100644
--- a/drivers/gpu/drm/gma500/fbdev.c
+++ b/drivers/gpu/drm/gma500/fbdev.c
@@ -108,7 +108,7 @@ int psb_fbdev_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
 	struct drm_device *dev = fb_helper->dev;
 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 	struct pci_dev *pdev = to_pci_dev(dev->dev);
-	struct fb_info *info;
+	struct fb_info *info = fb_helper->info;
 	struct drm_framebuffer *fb;
 	struct drm_mode_fb_cmd2 mode_cmd = { };
 	int size;
@@ -167,12 +167,6 @@ int psb_fbdev_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
 	fb_helper->funcs = &psb_fbdev_fb_helper_funcs;
 	fb_helper->fb = fb;
 
-	info = drm_fb_helper_alloc_info(fb_helper);
-	if (IS_ERR(info)) {
-		ret = PTR_ERR(info);
-		goto err_drm_framebuffer_unregister_private;
-	}
-
 	info->fbops = &psb_fbdev_fb_ops;
 
 	/* Accessed stolen memory directly */
@@ -196,10 +190,6 @@ int psb_fbdev_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
 
 	return 0;
 
-err_drm_framebuffer_unregister_private:
-	drm_framebuffer_unregister_private(fb);
-	drm_framebuffer_cleanup(fb);
-	kfree(fb);
 err_drm_gem_object_put:
 	drm_gem_object_put(obj);
 	return ret;