bochs: convert to drm_fb_helper_fbdev_setup/teardown

Currently unloading bochs_drm (after unbinding the vtconsole) results in
a warning about a leaked connector:

    [drm:drm_mode_config_cleanup] *ERROR* connector Virtual-3 leaked!

While investigating a potential fix I noticed that a lot of open-coded
functionality is already implemented elsewhere, so start converting it:
bochs_fbdev_init -> drm_fb_helper_fbdev_setup: trivial (similar impl).
bochs_fbdev_fini -> drm_fb_helper_fbdev_teardown: requires unembedding
"struct drm_framebuffer" from "struct bochs_framebuffer".

Unembedding drm_framebuffer is made easy using drm_gem_fbdev_fb_create
which can replace bochs_fbdev_destroy and custom routines in bochs_mm.c.
For this to work, the GEM object is moved into "drm_framebuffer". After
that, "bochs_framebuffer" is no longer needed and therefore removed.

Remove the unused "size" and "initialized" fields from fb, the latter is
not necessary as drm_fb_helper_fbdev_teardown can be called even if
bochsfb_create fails. This theory was tested by returning early and
late (just before drm_gem_fbdev_fb_create). Both scenarios fail
gracefully although the latter seems to leak the object from
bochsfb_create_object (not a regression).

Guess on the reason for the encoder leak: drm_framebuffer_cleanup was
previously used, but did not destroy much. drm_fb_helper_fbdev_teardown
is now used and calls drm_framebuffer_remove which does a bit more work.

Tested with 'echo 0 > /sys/class/vtconsole/vtcon1/bind; rmmod bochs_drm'
and also with Xorg + fbdev (startx -> xterm). The latter triggered a
warning in ttm_bo_vm_open that existed before, see
https://lkml.kernel.org/r/1464000533-13140-4-git-send-email-mstaudt@suse.de

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Link: http://patchwork.freedesktop.org/patch/msgid/20180906221810.20170-3-peter@lekensteyn.nl
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 3 insertions, 16 deletions

diff --git a/drivers/gpu/drm/bochs/bochs.h b/drivers/gpu/drm/bochs/bochs.h
index 375bf92cd04f..8514a84fbdbe 100644
--- a/drivers/gpu/drm/bochs/bochs.h
+++ b/drivers/gpu/drm/bochs/bochs.h
@@ -51,11 +51,6 @@ enum bochs_types {
 	BOCHS_UNKNOWN,
 };
 
-struct bochs_framebuffer {
-	struct drm_framebuffer base;
-	struct drm_gem_object *obj;
-};
-
 struct bochs_device {
 	/* hw */
 	void __iomem   *mmio;
@@ -88,15 +83,11 @@ struct bochs_device {
 
 	/* fbdev */
 	struct {
-		struct bochs_framebuffer gfb;
+		struct drm_framebuffer *fb;
 		struct drm_fb_helper helper;
-		int size;
-		bool initialized;
 	} fb;
 };
 
-#define to_bochs_framebuffer(x) container_of(x, struct bochs_framebuffer, base)
-
 struct bochs_bo {
 	struct ttm_buffer_object bo;
 	struct ttm_placement placement;
@@ -148,15 +139,9 @@ int bochs_dumb_create(struct drm_file *file, struct drm_device *dev,
 int bochs_dumb_mmap_offset(struct drm_file *file, struct drm_device *dev,
 			   uint32_t handle, uint64_t *offset);
 
-int bochs_framebuffer_init(struct drm_device *dev,
-			   struct bochs_framebuffer *gfb,
-			   const struct drm_mode_fb_cmd2 *mode_cmd,
-			   struct drm_gem_object *obj);
 int bochs_bo_pin(struct bochs_bo *bo, u32 pl_flag, u64 *gpu_addr);
 int bochs_bo_unpin(struct bochs_bo *bo);
 
-extern const struct drm_mode_config_funcs bochs_mode_funcs;
-
 /* bochs_kms.c */
 int bochs_kms_init(struct bochs_device *bochs);
 void bochs_kms_fini(struct bochs_device *bochs);
@@ -164,3 +149,5 @@ void bochs_kms_fini(struct bochs_device *bochs);
 /* bochs_fbdev.c */
 int bochs_fbdev_init(struct bochs_device *bochs);
 void bochs_fbdev_fini(struct bochs_device *bochs);
+
+extern const struct drm_mode_config_funcs bochs_mode_funcs;