[PATCH v2 3/7] fbcon: Implement struct consw.con_unblank

[Thomas Zimmermann <tzimmermann@suse.de>]

Implement con_unblank from struct consw with the !blank branches from
fbcon_blank(). The new function is called fbcon_unblank(). Remove the
duplicated code from fbcon_blank().

Fbcon tracks fbdev blank state in par->blank_state using fbdev's FB_BLANK
constants. In fbcon_unblank() the stored value is always FB_BLANK_UNBLANK.
In fbcon_blank(), the new blank state is 1 + plus the VESA blank mode
given in the parameter blank.

fbcon_blank() now disables the cursor worker unconditionally.

Unblanking while switching the console from graphics to text mode
requires setting the display with fb_set_var(). fbcon_unblank() does not
receive the mode_switch flag from its caller, so track the flag with the
par->graphics and vc->vc_num fields. A later update might add a mode-
switching callback to simplify this logic.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/video/fbdev/core/fbcon.c | 56 ++++++++++++++++++++++----------
 1 file changed, 39 insertions(+), 17 deletions(-)

diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 615fa596b7cc..6d564111ebd0 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2293,32 +2293,53 @@ static bool fbcon_blank(struct vc_data *vc, enum vesa_blank_mode blank,
 	struct fb_info *info = fbcon_info_from_console(vc->vc_num);
 	struct fbcon_par *par = info->fbcon_par;
 
-	if (mode_switch) {
-		struct fb_var_screeninfo var = info->var;
+	if (mode_switch)
+		par->graphics = true;
 
-		par->graphics = 1;
+	if (fbcon_is_active(vc, info)) {
+		int blank_state = 1 + blank; /* convert VESA to FB_BLANK constant */
 
-		if (!blank) {
-			var.activate = FB_ACTIVATE_NOW | FB_ACTIVATE_FORCE |
-				FB_ACTIVATE_KD_TEXT;
-			fb_set_var(info, &var);
-			par->graphics = 0;
-			par->var = info->var;
+		if (par->blank_state != blank_state) {
+			par->blank_state = blank_state;
+			fbcon_cursor(vc, false);
+			par->cursor_flash = false;
+
+			if (fb_blank(info, blank_state))
+				fbcon_generic_blank(vc, info, true);
 		}
 	}
 
+	fbcon_del_cursor_work(info);
+
+	return false;
+}
+
+static bool fbcon_unblank(struct vc_data *vc)
+{
+	struct fb_info *info = fbcon_info_from_console(vc->vc_num);
+	struct fbcon_par *par = info->fbcon_par;
+	bool mode_switch = par->graphics && vc->vc_mode == KD_TEXT;
+
+	if (mode_switch) {
+		struct fb_var_screeninfo var = info->var;
+
+		var.activate = FB_ACTIVATE_NOW | FB_ACTIVATE_FORCE | FB_ACTIVATE_KD_TEXT;
+		fb_set_var(info, &var);
+		par->graphics = false;
+		par->var = info->var;
+	}
+
 	if (fbcon_is_active(vc, info)) {
-		if (par->blank_state != blank) {
-			par->blank_state = blank;
-			fbcon_cursor(vc, !blank);
-			par->cursor_flash = (!blank);
+		if (par->blank_state != FB_BLANK_UNBLANK) {
+			par->blank_state = FB_BLANK_UNBLANK;
+			fbcon_cursor(vc, true);
+			par->cursor_flash = true;
 
-			if (fb_blank(info, blank))
-				fbcon_generic_blank(vc, info, blank);
+			if (fb_blank(info, FB_BLANK_UNBLANK))
+				fbcon_generic_blank(vc, info, false);
 		}
 
-		if (!blank)
-			update_screen(vc);
+		update_screen(vc);
 	}
 
 	if (mode_switch || !fbcon_is_active(vc, info) || par->blank_state != FB_BLANK_UNBLANK)
@@ -3168,6 +3189,7 @@ static const struct consw fb_con = {
 	.con_scroll 		= fbcon_scroll,
 	.con_switch 		= fbcon_switch,
 	.con_blank 		= fbcon_blank,
+	.con_unblank		= fbcon_unblank,
 	.con_font_set 		= fbcon_set_font,
 	.con_font_get 		= fbcon_get_font,
 	.con_font_default	= fbcon_set_def_font,
-- 
2.55.0