Gentoo Archives: gentoo-user

From: Alan Mackenzie <acm@×××.de>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] console scrollback (kernel 5.14)
Date: Wed, 22 Sep 2021 20:29:07
Message-Id: YUuSCwpAfk/yZaII@ACM
In Reply to: [gentoo-user] console scrollback (kernel 5.14) by Jorge Almeida
1 Hello, Jorge.
2
3 On Sat, Sep 18, 2021 at 21:40:46 +0100, Jorge Almeida wrote:
4 > Hello, gentooers in general and Alan in particular
5
6 > I've been using Alan Mackenzie's patch until kernel 5.13, with
7 > success. It failed with 5.14.4 --yes, I know, but it doesn't hurt to
8 > try :)
9
10 I'm happy to know my patch is still useful.
11
12 I must confess that somebody told me by private email that it fails on
13 systems which change their screen geometry during boot-up. For example,
14 a system which first boots into 80x25, then changes to a frame buffer.
15 I know why this is happening, but I don't have a machine to debug it on,
16 so the debugging is happening slowly, with the help of my correspondent.
17
18 It also doesn't seem to work on machines with kernel parameters such as
19 vga=791.
20
21 That said, I'm hoping that the failure of the patch on 5.14.4 is just a
22 simple struct change in 5.14, which I hope to have corrected (but in
23 5.14.5). What used to be
24
25 while (!tty->stopped ...
26
27 has now become
28
29 while (!tty->flow.stopped ...
30
31 I'm assuming that the patch you tried to apply was
32 5.10.49-scroll.20210715.diff. If so, please leave it applied (with the
33 one failed hunk), and additionally apply this:
34
35
36
37 --- ./drivers/tty/vt/vt.c.orig 2020-12-13 22:41:30.000000000 +0000
38 +++ ./drivers/tty/vt/vt.c 2021-04-05 16:20:32.624563241 +0000
39 @@ -3208,6 +3208,12 @@
40
41 param.vc = vc;
42
43 +#ifdef CONFIG_FRAMEBUFFER_CONSOLE_SOFT_SCROLLBACK
44 + /* Undo any soft scrolling - <Alt><Fn> and <Shift><PgUp/Down> do
45 + not pass through this function. */
46 + concon_set_origin (vc);
47 +#endif
48 +
49 while (!tty->flow.stopped && count) {
50 int orig = *buf;
51 buf++;
52
53
54 As always, there are no guarantees. Please let me know whether or not
55 the above hunk applies, and if so, whether or not the scrolling still
56 works. (Also, feel free to send me private email if there're any
57 problems with the mechanics of applying the patch.)
58
59 Thanks!
60
61 > Jorge Almeida
62
63 > Just in case it is useful:
64
65 It was, thanks!
66
67 [ .... ]
68
69 > param.vc = vc;
70
71 > + /* NEW STOUGH, 2021-04-03 */
72 > +#ifdef CONFIG_FRAMEBUFFER_CONSOLE_SOFT_SCROLLBACK
73 > + /* Undo any soft scrolling - <Alt><Fn> and <Shift><PgUp/Down> do
74 > + not pass through this function. */
75 > + concon_set_origin (vc);
76 > +#endif
77 > + /* END OF NEW STOUGH */
78 > +
79 > while (!tty->stopped && count) { <==========================
80 > int orig = *buf;
81 > buf++;
82
83 --
84 Alan Mackenzie (Nuremberg, Germany).

Replies

Subject Author
Re: [gentoo-user] console scrollback (kernel 5.14) Jorge Almeida <jjalmeida@×××××.com>