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authorJiri Slaby <jslaby@suse.cz>2016-10-03 12:18:35 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-10-27 17:37:44 +0300
commit35cc56f9a30480c8a0cca809cf341614a2144758 (patch)
treef7edce136762932eaad0c7a448c72e3a1df3006d /drivers/tty/vt
parent89765b9424eafb954b1ca167a00c2a10e4f025be (diff)
downloadlinux-35cc56f9a30480c8a0cca809cf341614a2144758.tar.xz
tty: vgacon+sisusb, move scrolldelta to a common helper
The code is mirrorred in scrolldelta implementations of both vgacon and sisusb. Let's move the code to a separate helper where we will perform a common cleanup and further changes. While we are moving the code, make it linear and save one indentation level. This is done by returning from the "!lines" then-branch immediatelly. This allows flushing the else-branch 1 level to the left, obviously. Few more new lines and comments were added too. And do not forget to export the helper function given sisusb can be built as module. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Thomas Winischhofer <thomas@winischhofer.net> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: <linux-fbdev@vger.kernel.org> Cc: <linux-usb@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/vt')
-rw-r--r--drivers/tty/vt/vt.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index a0b7576747cd..2eab714aab67 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -4279,6 +4279,44 @@ void vcs_scr_updated(struct vc_data *vc)
notify_update(vc);
}
+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;
+ int margin = c->vc_size_row * 4;
+ int ul, we, p, st;
+
+ /* Turn scrollback off */
+ if (!lines) {
+ c->vc_visible_origin = c->vc_origin;
+ return;
+ }
+
+ /* 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;
+ 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;
+
+ /* Only a little piece would be left? Show all incl. the piece! */
+ if (st < 2 * margin)
+ margin = 0;
+ if (p < margin)
+ p = 0;
+ if (p > st - margin)
+ p = st;
+
+ c->vc_visible_origin = ubase + (p + ul) % we;
+}
+EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
+
/*
* Visible symbols for modules
*/