tty: vt, consw->con_scrolldelta cleanup

* allow NULL consw->con_scrolldelta (some consoles define an empty
  hook)
* => remove empty hooks now
* return value of consw->con_scrolldelta is never checked => make the
  function void
* document consw->con_scrolldelta a bit

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: linux-usb@vger.kernel.org
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index abc79ae..365a91d 100644 (file)
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -2468,7 +2468,7 @@ static void console_callback(struct work_struct *ignored)
        if (scrollback_delta) {
                struct vc_data *vc = vc_cons[fg_console].d;
                clear_selection();
-               if (vc->vc_mode == KD_TEXT)
+               if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
                        vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
                scrollback_delta = 0;
        }

diff --git a/drivers/usb/misc/sisusbvga/sisusb_con.c b/drivers/usb/misc/sisusbvga/sisusb_con.c
index 0ebbf49..a8244eb 100644 (file)
--- a/drivers/usb/misc/sisusbvga/sisusb_con.c
+++ b/drivers/usb/misc/sisusbvga/sisusb_con.c
@@ -717,24 +717,22 @@ sisusbcon_blank(struct vc_data *c, int blank, int mode_switch)
 }
 
 /* interface routine */
-static int
+static void
 sisusbcon_scrolldelta(struct vc_data *c, int lines)
 {
        struct sisusb_usb_data *sisusb;
        int margin = c->vc_size_row * 4;
        int ul, we, p, st;
 
-       /* The return value does not seem to be used */
-
        sisusb = sisusb_get_sisusb_lock_and_check(c->vc_num);
        if (!sisusb)
-               return 0;
+               return;
 
        /* sisusb->lock is down */
 
        if (sisusb_is_inactive(c, sisusb)) {
                mutex_unlock(&sisusb->lock);
-               return 0;
+               return;
        }
 
        if (!lines)             /* Turn scrollback off */
@@ -774,8 +772,6 @@ sisusbcon_scrolldelta(struct vc_data *c, int lines)
        sisusbcon_set_start_address(sisusb, c);
 
        mutex_unlock(&sisusb->lock);
-
-       return 1;
 }
 
 /* Interface routine */
@@ -1433,7 +1429,6 @@ static const struct consw sisusb_dummy_con = {
        .con_font_default =     SISUSBCONDUMMY,
        .con_font_copy =        SISUSBCONDUMMY,
        .con_set_palette =      SISUSBCONDUMMY,
-       .con_scrolldelta =      SISUSBCONDUMMY,
 };
 
 int

diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index 0efc52f..9ce03b9 100644 (file)
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -72,6 +72,5 @@ const struct consw dummy_con = {
     .con_font_default =        DUMMY,
     .con_font_copy =   DUMMY,
     .con_set_palette = DUMMY,
-    .con_scrolldelta = DUMMY,
 };
 EXPORT_SYMBOL_GPL(dummy_con);

diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index afd3301..eadc7bf 100644 (file)
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -171,7 +171,6 @@ static void fbcon_bmove(struct vc_data *vc, int sy, int sx, int dy, int dx,
 static int fbcon_switch(struct vc_data *vc);
 static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch);
 static int fbcon_set_palette(struct vc_data *vc, const unsigned char *table);
-static int fbcon_scrolldelta(struct vc_data *vc, int lines);
 
 /*
  *  Internal routines
@@ -2765,7 +2764,7 @@ static void fbcon_invert_region(struct vc_data *vc, u16 * p, int cnt)
        }
 }
 
-static int fbcon_scrolldelta(struct vc_data *vc, int lines)
+static void fbcon_scrolldelta(struct vc_data *vc, int lines)
 {
        struct fb_info *info = registered_fb[con2fb_map[fg_console]];
        struct fbcon_ops *ops = info->fbcon_par;
@@ -2774,9 +2773,9 @@ static int fbcon_scrolldelta(struct vc_data *vc, int lines)
 
        if (softback_top) {
                if (vc->vc_num != fg_console)
-                       return 0;
+                       return;
                if (vc->vc_mode != KD_TEXT || !lines)
-                       return 0;
+                       return;
                if (logo_shown >= 0) {
                        struct vc_data *conp2 = vc_cons[logo_shown].d;
 
@@ -2809,11 +2808,11 @@ static int fbcon_scrolldelta(struct vc_data *vc, int lines)
                fbcon_cursor(vc, CM_ERASE | CM_SOFTBACK);
                fbcon_redraw_softback(vc, disp, lines);
                fbcon_cursor(vc, CM_DRAW | CM_SOFTBACK);
-               return 0;
+               return;
        }
 
        if (!scrollback_phys_max)
-               return -ENOSYS;
+               return;
 
        scrollback_old = scrollback_current;
        scrollback_current -= lines;
@@ -2822,10 +2821,10 @@ static int fbcon_scrolldelta(struct vc_data *vc, int lines)
        else if (scrollback_current > scrollback_max)
                scrollback_current = scrollback_max;
        if (scrollback_current == scrollback_old)
-               return 0;
+               return;
 
        if (fbcon_is_inactive(vc, info))
-               return 0;
+               return;
 
        fbcon_cursor(vc, CM_ERASE);
 
@@ -2852,7 +2851,6 @@ static int fbcon_scrolldelta(struct vc_data *vc, int lines)
 
        if (!scrollback_current)
                fbcon_cursor(vc, CM_DRAW);
-       return 0;
 }
 
 static int fbcon_set_origin(struct vc_data *vc)

diff --git a/drivers/video/console/mdacon.c b/drivers/video/console/mdacon.c
index 8edc062..234af26 100644 (file)
--- a/drivers/video/console/mdacon.c
+++ b/drivers/video/console/mdacon.c
@@ -505,11 +505,6 @@ static int mdacon_blank(struct vc_data *c, int blank, int mode_switch)
        }
 }
 
-static int mdacon_scrolldelta(struct vc_data *c, int lines)
-{
-       return 0;
-}
-
 static void mdacon_cursor(struct vc_data *c, int mode)
 {
        if (mode == CM_ERASE) {
@@ -578,7 +573,6 @@ static const struct consw mda_con = {
        .con_switch =           mdacon_switch,
        .con_blank =            mdacon_blank,
        .con_set_palette =      mdacon_set_palette,
-       .con_scrolldelta =      mdacon_scrolldelta,
        .con_build_attr =       mdacon_build_attr,
        .con_invert_region =    mdacon_invert_region,
 };

diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 0553dfe..eb3d4ce 100644 (file)
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -579,12 +579,6 @@ static int newport_set_palette(struct vc_data *vc, const unsigned char *table)
        return -EINVAL;
 }
 
-static int newport_scrolldelta(struct vc_data *vc, int lines)
-{
-       /* there is (nearly) no off-screen memory, so we can't scroll back */
-       return 0;
-}
-
 static int newport_scroll(struct vc_data *vc, int t, int b, int dir,
                          int lines)
 {
@@ -735,7 +729,6 @@ const struct consw newport_con = {
        .con_font_set     = newport_font_set,
        .con_font_default = newport_font_default,
        .con_set_palette  = newport_set_palette,
-       .con_scrolldelta  = newport_scrolldelta,
        .con_set_origin   = DUMMY,
        .con_save_screen  = DUMMY
 };

diff --git a/drivers/video/console/sticon.c b/drivers/video/console/sticon.c
index e440c2d..20f6a2f 100644 (file)
--- a/drivers/video/console/sticon.c
+++ b/drivers/video/console/sticon.c
@@ -256,11 +256,6 @@ static int sticon_blank(struct vc_data *c, int blank, int mode_switch)
     return 1;
 }
 
-static int sticon_scrolldelta(struct vc_data *conp, int lines)
-{
-    return 0;
-}
-
 static u16 *sticon_screen_pos(struct vc_data *conp, int offset)
 {
     int line;
@@ -359,7 +354,6 @@ static const struct consw sti_con = {
        .con_switch             = sticon_switch,
        .con_blank              = sticon_blank,
        .con_set_palette        = sticon_set_palette,
-       .con_scrolldelta        = sticon_scrolldelta,
        .con_set_origin         = sticon_set_origin,
        .con_save_screen        = sticon_save_screen, 
        .con_build_attr         = sticon_build_attr,

diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 8bf9110..f447d69 100644 (file)
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -80,7 +80,7 @@ static void vgacon_deinit(struct vc_data *c);
 static void vgacon_cursor(struct vc_data *c, int mode);
 static int vgacon_switch(struct vc_data *c);
 static int vgacon_blank(struct vc_data *c, int blank, int mode_switch);
-static int vgacon_scrolldelta(struct vc_data *c, int lines);
+static void vgacon_scrolldelta(struct vc_data *c, int lines);
 static int vgacon_set_origin(struct vc_data *c);
 static void vgacon_save_screen(struct vc_data *c);
 static int vgacon_scroll(struct vc_data *c, int t, int b, int dir,
@@ -248,18 +248,18 @@ static void vgacon_restore_screen(struct vc_data *c)
        }
 }
 
-static int vgacon_scrolldelta(struct vc_data *c, int lines)
+static void vgacon_scrolldelta(struct vc_data *c, int lines)
 {
        int start, end, count, soff;
 
        if (!lines) {
                c->vc_visible_origin = c->vc_origin;
                vga_set_mem_top(c);
-               return 1;
+               return;
        }
 
        if (!vgacon_scrollback)
-               return 1;
+               return;
 
        if (!vgacon_scrollback_save) {
                vgacon_cursor(c, CM_ERASE);
@@ -320,8 +320,6 @@ static int vgacon_scrolldelta(struct vc_data *c, int lines)
                        scr_memcpyw(d, s, diff * c->vc_size_row);
        } else
                vgacon_cursor(c, CM_MOVE);
-
-       return 1;
 }
 #else
 #define vgacon_scrollback_startup(...) do { } while (0)
@@ -334,7 +332,7 @@ static void vgacon_restore_screen(struct vc_data *c)
                vgacon_scrolldelta(c, 0);
 }
 
-static int vgacon_scrolldelta(struct vc_data *c, int lines)
+static void vgacon_scrolldelta(struct vc_data *c, int lines)
 {
        if (!lines)             /* Turn scrollback off */
                c->vc_visible_origin = c->vc_origin;
@@ -362,7 +360,6 @@ static int vgacon_scrolldelta(struct vc_data *c, int lines)
                c->vc_visible_origin = vga_vram_base + (p + ul) % we;
        }
        vga_set_mem_top(c);
-       return 1;
 }
 #endif /* CONFIG_VGACON_SOFT_SCROLLBACK */
 

diff --git a/include/linux/console.h b/include/linux/console.h
index 98c8615..d175de8 100644 (file)
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -28,6 +28,12 @@ struct tty_struct;
 #define VT100ID "\033[?1;2c"
 #define VT102ID "\033[?6c"
 
+/**
+ * struct consw - callbacks for consoles
+ *
+ * @con_scrolldelta: the contents of the console should be scrolled by @lines.
+ *                  Invoked by user. (optional)
+ */
 struct consw {
        struct module *owner;
        const char *(*con_startup)(void);
@@ -48,7 +54,7 @@ struct consw {
        int     (*con_resize)(struct vc_data *, unsigned int, unsigned int,
                               unsigned int);
        int     (*con_set_palette)(struct vc_data *, const unsigned char *);
-       int     (*con_scrolldelta)(struct vc_data *, int);
+       void    (*con_scrolldelta)(struct vc_data *, int lines);
        int     (*con_set_origin)(struct vc_data *);
        void    (*con_save_screen)(struct vc_data *);
        u8      (*con_build_attr)(struct vc_data *, u8, u8, u8, u8, u8, u8);