tty: vt, compute vc offsets in advance (210fd746) · Commits · 戴 / test

drivers/tty/vt/vt.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -4283,6 +4283,9 @@ void vc_scrolldelta_helper(struct vc_data *c, int lines,
		unsigned int rolled_over, void *base, unsigned int size)
		{
		unsigned long ubase = (unsigned long)base;
		ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
		ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
		ptrdiff_t origin = (void *)c->vc_origin - base;
		int margin = c->vc_size_row * 4;
		int ul, we, p, st;

		@@ -4293,17 +4296,16 @@ void vc_scrolldelta_helper(struct vc_data *c, int lines,
		}

		/* Do we have already enough to allow jumping from 0 to the end? */
		if (rolled_over > (c->vc_scr_end - ubase) + margin) {
		ul = c->vc_scr_end - ubase;
		if (rolled_over > scr_end + margin) {
		ul = scr_end;
		we = rolled_over + c->vc_size_row;
		} else {
		ul = 0;
		we = size;
		}

		p = (c->vc_visible_origin - ubase - ul + we) % we +
		lines * c->vc_size_row;
		st = (c->vc_origin - ubase - ul + we) % we;
		p = (vorigin - ul + we) % we + lines * c->vc_size_row;
		st = (origin - ul + we) % we;

		/* Only a little piece would be left? Show all incl. the piece! */
		if (st < 2 * margin)