Commit bd6026a8 authored by Daniel Vetter's avatar Daniel Vetter
Browse files

fbcon: Extract fbcon_open/release helpers 



There's two minor behaviour changes in here:
- in error paths we now consistently call fb_ops->fb_release
- fb_release really can't fail (fbmem.c ignores it too) and there's no
  reasonable cleanup we can do anyway.

Note that everything in fbcon.c is protected by the big console_lock()
lock (especially all the global variables), so the minor changes in
ordering of setup/cleanup do not matter.

v2: Explain a bit better why this is all correct (Sam)

Acked-by: default avatarSam Ravnborg <sam@ravnborg.org>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Du Cheng <ducheng2@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-10-daniel.vetter@ffwll.ch
parent 6b2060cf

drivers/video/fbdev/core/fbcon.c

+53 −54
Original line number Diff line number Diff line
@@ -682,19 +682,37 @@ static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount) 


#endif /* CONFIG_MISC_TILEBLITTING */



static int fbcon_open(struct fb_info *info)

{

	if (!try_module_get(info->fbops->owner))

		return -ENODEV;



	if (info->fbops->fb_open &&

	    info->fbops->fb_open(info, 0)) {

		module_put(info->fbops->owner);

		return -ENODEV;

	}



	return 0;

}



static void fbcon_release(struct fb_info *info)

{

	if (info->fbops->fb_release)

		info->fbops->fb_release(info, 0);



	module_put(info->fbops->owner);

}



static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info,

				  int unit, int oldidx)

{

	struct fbcon_ops *ops = NULL;

	int err = 0;

	int err;



	if (!try_module_get(info->fbops->owner))

		err = -ENODEV;



	if (!err && info->fbops->fb_open &&

	    info->fbops->fb_open(info, 0))

		err = -ENODEV;

	err = fbcon_open(info);

	if (err)

		return err;



	if (!err) {

		ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
@@ -715,7 +733,7 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, 


	if (err) {

		con2fb_map[unit] = oldidx;

		module_put(info->fbops->owner);

		fbcon_release(info);

	}



	return err;
@@ -726,19 +744,10 @@ static int con2fb_release_oldinfo(struct vc_data *vc, struct fb_info *oldinfo, 
				  int oldidx, int found)

{

	struct fbcon_ops *ops = oldinfo->fbcon_par;

	int err = 0, ret;

	int ret;



	if (oldinfo->fbops->fb_release &&

	    oldinfo->fbops->fb_release(oldinfo, 0)) {

		con2fb_map[unit] = oldidx;

		if (!found && newinfo->fbops->fb_release)

			newinfo->fbops->fb_release(newinfo, 0);

		if (!found)

			module_put(newinfo->fbops->owner);

		err = -ENODEV;

	}

	fbcon_release(oldinfo);



	if (!err) {

	fbcon_del_cursor_work(oldinfo);

	kfree(ops->cursor_state.mask);

	kfree(ops->cursor_data);
@@ -746,7 +755,6 @@ static int con2fb_release_oldinfo(struct vc_data *vc, struct fb_info *oldinfo, 
	kfree(ops->fontbuffer);

	kfree(oldinfo->fbcon_par);

	oldinfo->fbcon_par = NULL;

		module_put(oldinfo->fbops->owner);

	/*

	  If oldinfo and newinfo are driving the same hardware,

	  the fb_release() method of oldinfo may attempt to
@@ -762,9 +770,8 @@ static int con2fb_release_oldinfo(struct vc_data *vc, struct fb_info *oldinfo, 
				"detected unhandled fb_set_par error, "

				"error code %d\n", ret);

	}

	}



	return err;

	return 0;

}



static void con2fb_init_display(struct vc_data *vc, struct fb_info *info,
@@ -919,7 +926,6 @@ static const char *fbcon_startup(void) 
	struct fbcon_display *p = &fb_display[fg_console];

	struct vc_data *vc = vc_cons[fg_console].d;

	const struct font_desc *font = NULL;

	struct module *owner;

	struct fb_info *info = NULL;

	struct fbcon_ops *ops;

	int rows, cols;
@@ -938,17 +944,12 @@ static const char *fbcon_startup(void) 
	if (!info)

		return NULL;

	

	owner = info->fbops->owner;

	if (!try_module_get(owner))

		return NULL;

	if (info->fbops->fb_open && info->fbops->fb_open(info, 0)) {

		module_put(owner);

	if (fbcon_open(info))

		return NULL;

	}



	ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);

	if (!ops) {

		module_put(owner);

		fbcon_release(info);

		return NULL;

	}
@@ -3314,10 +3315,6 @@ static void fbcon_exit(void) 
		}



		if (mapped) {

			if (info->fbops->fb_release)

				info->fbops->fb_release(info, 0);

			module_put(info->fbops->owner);



			if (info->fbcon_par) {

				struct fbcon_ops *ops = info->fbcon_par;
@@ -3327,6 +3324,8 @@ static void fbcon_exit(void) 
				kfree(info->fbcon_par);

				info->fbcon_par = NULL;

			}



			fbcon_release(info);

		}

	}

}