[PATCH] Staging: speakup: read scrolled-back VT

From: Samuel Thibault
Date: Sun Jan 24 2016 - 19:32:17 EST


Previously, speakup would always read the non-scrolled part of the VT,
even when the VT is scrolled back with shift-page. This patch makes
vt.c export screen_pos so that speakup can use it to properly access
the content of the scrolled-back VT.

This was tested with both vgacon and fbcon.

Signed-off-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
Reviewed-by: Alan Cox <alan@xxxxxxxxxxxxxxx>

--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -4250,6 +4250,7 @@ unsigned short *screen_pos(struct vc_dat
{
return screenpos(vc, 2 * w_offset, viewed);
}
+EXPORT_SYMBOL_GPL(screen_pos);

void getconsxy(struct vc_data *vc, unsigned char *p)
{
--- a/drivers/staging/speakup/main.c
+++ b/drivers/staging/speakup/main.c
@@ -264,8 +264,9 @@ static struct notifier_block vt_notifier
.notifier_call = vt_notifier_call,
};

-static unsigned char get_attributes(u16 *pos)
+static unsigned char get_attributes(struct vc_data *vc, u16 *pos)
{
+ pos = screen_pos(vc, pos - (u16 *)vc->vc_origin, 1);
return (u_char) (scr_readw(pos) >> 8);
}

@@ -275,7 +276,7 @@ static void speakup_date(struct vc_data
spk_y = spk_cy = vc->vc_y;
spk_pos = spk_cp = vc->vc_pos;
spk_old_attr = spk_attr;
- spk_attr = get_attributes((u_short *) spk_pos);
+ spk_attr = get_attributes(vc, (u_short *)spk_pos);
}

static void bleep(u_short val)
@@ -469,8 +470,12 @@ static u16 get_char(struct vc_data *vc,
u16 ch = ' ';

if (vc && pos) {
- u16 w = scr_readw(pos);
- u16 c = w & 0xff;
+ u16 w;
+ u16 c;
+
+ pos = screen_pos(vc, pos - (u16 *)vc->vc_origin, 1);
+ w = scr_readw(pos);
+ c = w & 0xff;

if (w & vc->vc_hi_font_mask)
c |= 0x100;
@@ -746,7 +751,7 @@ static int get_line(struct vc_data *vc)
u_char tmp2;

spk_old_attr = spk_attr;
- spk_attr = get_attributes((u_short *) spk_pos);
+ spk_attr = get_attributes(vc, (u_short *)spk_pos);
for (i = 0; i < vc->vc_cols; i++) {
buf[i] = (u_char) get_char(vc, (u_short *) tmp, &tmp2);
tmp += 2;
@@ -811,7 +816,7 @@ static int say_from_to(struct vc_data *v
u_short saved_punc_mask = spk_punc_mask;

spk_old_attr = spk_attr;
- spk_attr = get_attributes((u_short *) from);
+ spk_attr = get_attributes(vc, (u_short *)from);
while (from < to) {
buf[i++] = (char)get_char(vc, (u_short *) from, &tmp);
from += 2;
@@ -886,7 +891,7 @@ static int get_sentence_buf(struct vc_da
sentmarks[bn][0] = &sentbuf[bn][0];
i = 0;
spk_old_attr = spk_attr;
- spk_attr = get_attributes((u_short *) start);
+ spk_attr = get_attributes(vc, (u_short *)start);

while (start < end) {
sentbuf[bn][i] = (char)get_char(vc, (u_short *) start, &tmp);
@@ -1585,7 +1590,7 @@ static int count_highlight_color(struct
u16 *ptr;

for (ptr = start; ptr < end; ptr++) {
- ch = get_attributes(ptr);
+ ch = get_attributes(vc, ptr);
bg = (ch & 0x70) >> 4;
speakup_console[vc_num]->ht.bgcount[bg]++;
}