fbdev: Wrap user-invoked calls to fb_set_var() in helper

Handle fbcon during display updates in fb_set_var_from_user(). Check
with fbcon if the mode change is possible, update hardware state and
finally update fbcon. Update all callers.

Only the FBIOPUT_VSCREENINFO ioctl currently does all steps. Other
mode-changes callers in sysfs and driver code are missing fbcon-related
steps.

With the new helper, ps3fb and sh_mobile_lcdcfb no longer maintain
fbcon state themselves.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>

drivers/video/fbdev/core/fb_chrdev.c

@@ -85,11 +85,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
 		var.activate &= ~FB_ACTIVATE_KD_TEXT;
 		console_lock();
 		lock_fb_info(info);
-		ret = fbcon_modechange_possible(info, &var);
-		if (!ret)
-			ret = fb_set_var(info, &var);
-		if (!ret)
-			fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
+		ret = fb_set_var_from_user(info, &var);
 		unlock_fb_info(info);
 		console_unlock();
 		if (!ret && copy_to_user(argp, &var, sizeof(var)))

drivers/video/fbdev/core/fbcon.c

@@ -2701,7 +2701,6 @@ void fbcon_update_vcs(struct fb_info *info, bool all)
 	else
 		fbcon_modechanged(info);
 }
-EXPORT_SYMBOL(fbcon_update_vcs);
 
 /* let fbcon check if it supports a new screen resolution */
 int fbcon_modechange_possible(struct fb_info *info, struct fb_var_screeninfo *var)
@@ -2729,7 +2728,6 @@ int fbcon_modechange_possible(struct fb_info *info, struct fb_var_screeninfo *va
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(fbcon_modechange_possible);
 
 int fbcon_mode_deleted(struct fb_info *info,
 		       struct fb_videomode *mode)

drivers/video/fbdev/core/fbmem.c

@@ -346,6 +346,19 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 }
 EXPORT_SYMBOL(fb_set_var);
 
+int fb_set_var_from_user(struct fb_info *info, struct fb_var_screeninfo *var)
+{
+	int ret = fbcon_modechange_possible(info, var);
+
+	if (!ret)
+		ret = fb_set_var(info, var);
+	if (!ret)
+		fbcon_update_vcs(info, var->activate & FB_ACTIVATE_ALL);
+
+	return ret;
+}
+EXPORT_SYMBOL(fb_set_var_from_user);
+
 static void fb_lcd_notify_blank(struct fb_info *info)
 {
 	int power;

drivers/video/fbdev/core/fbsysfs.c

@@ -19,9 +19,7 @@ static int activate(struct fb_info *fb_info, struct fb_var_screeninfo *var)
 	var->activate |= FB_ACTIVATE_FORCE;
 	console_lock();
 	lock_fb_info(fb_info);
-	err = fb_set_var(fb_info, var);
-	if (!err)
-		fbcon_update_vcs(fb_info, var->activate & FB_ACTIVATE_ALL);
+	err = fb_set_var_from_user(fb_info, var);
 	unlock_fb_info(fb_info);
 	console_unlock();
 	if (err)

drivers/video/fbdev/ps3fb.c

@@ -29,7 +29,6 @@
 #include <linux/freezer.h>
 #include <linux/uaccess.h>
 #include <linux/fb.h>
-#include <linux/fbcon.h>
 #include <linux/init.h>
 
 #include <asm/cell-regs.h>
@@ -830,9 +829,7 @@ static int ps3fb_ioctl(struct fb_info *info, unsigned int cmd,
 				/* Force, in case only special bits changed */
 				var.activate |= FB_ACTIVATE_FORCE;
 				par->new_mode_id = val;
-				retval = fb_set_var(info, &var);
-				if (!retval)
-					fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
+				retval = fb_set_var_from_user(info, &var);
 				console_unlock();
 			}
 			break;

drivers/video/fbdev/sh_mobile_lcdcfb.c

@@ -15,7 +15,6 @@
 #include <linux/ctype.h>
 #include <linux/dma-mapping.h>
 #include <linux/delay.h>
-#include <linux/fbcon.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/ioctl.h>
@@ -1768,11 +1767,9 @@ static void sh_mobile_fb_reconfig(struct fb_info *info)
 	var.height = ch->display.height;
 	var.activate = FB_ACTIVATE_NOW;
 
-	if (fb_set_var(info, &var) < 0)
+	if (fb_set_var_from_user(info, &var) < 0)
 		/* Couldn't reconfigure, hopefully, can continue as before */
 		return;
-
-	fbcon_update_vcs(info, true);
 }
 
 /*

include/linux/fb.h

@@ -533,6 +533,8 @@ extern int fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var);
 extern int fb_pan_display(struct fb_info *info, struct fb_var_screeninfo *var);
 extern int fb_blank(struct fb_info *info, int blank);
 
+int fb_set_var_from_user(struct fb_info *info, struct fb_var_screeninfo *var);
+
 /*
  * Helpers for framebuffers in I/O memory
  */