[PATCH 05/16] tty: vt, consw->con_scrolldelta cleanup

From: Jiri Slaby
Date: Thu Jun 23 2016 - 07:42:25 EST

* 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@xxxxxxx>
Cc: Thomas Winischhofer <thomas@xxxxxxxxxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Cc: Jean-Christophe Plagniol-Villard <plagnioj@xxxxxxxxxxxx>
Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: linux-fbdev@xxxxxxxxxxxxxxx
Cc: linux-parisc@xxxxxxxxxxxxxxx
---
drivers/tty/vt/vt.c | 2 +-
drivers/usb/misc/sisusbvga/sisusb_con.c | 11 +++--------
drivers/video/console/dummycon.c | 1 -
drivers/video/console/fbcon.c | 16 +++++++---------
drivers/video/console/mdacon.c | 6 ------
drivers/video/console/newport_con.c | 7 -------
drivers/video/console/sticon.c | 6 ------
drivers/video/console/vgacon.c | 13 +++++--------
include/linux/console.h | 8 +++++++-
9 files changed, 23 insertions(+), 47 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index abc79ae19079..365a91d01a0e 100644
--- 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 0ebbf49cd649..a8244ebeb7a7 100644
--- 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 0efc52f11ad0..9ce03b9aba88 100644
--- 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 afd3301ac40c..eadc7bf62eb3 100644
--- 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 8edc062536a8..234af26b4829 100644
--- 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 0553dfe684ef..eb3d4ce12cd5 100644
--- 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 e440c2d9fe7c..20f6a2f5d4a7 100644
--- 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 8bf911002cba..f447d6916991 100644
--- 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 98c8615dc300..d175de8d7006 100644
--- 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);
--
2.9.0