Commit f0c7d2b7 authored by Francisco Jerez's avatar Francisco Jerez Committed by Linus Torvalds
Browse files

vgacon: prevent vgacon_deinit from touching the hardware for inactive consoles.



fbcon makes the (reasonable) assumption that it only needs to program the
hardware once, when fbcon_init() is called for the foreground console.

This doesn't always play well with vgacon because vgacon_deinit() is only
doing its job when the last console it owns is closed (when switching from
vgacon to fbcon, that's usually *after* fbcon_init() has set the new
mode).

Depending on the hardware this can cause the wrong framebuffer location to
be scanned out (e.g.  reproduced on nv05 with the nouveau framebuffer
driver).
Signed-off-by: default avatarFrancisco Jerez <currojerez@riseup.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2ddce3fd
......@@ -589,12 +589,14 @@ static void vgacon_init(struct vc_data *c, int init)
static void vgacon_deinit(struct vc_data *c)
{
/* When closing the last console, reset video origin */
if (!--vgacon_uni_pagedir[1]) {
/* When closing the active console, reset video origin */
if (CON_IS_VISIBLE(c)) {
c->vc_visible_origin = vga_vram_base;
vga_set_mem_top(c);
con_free_unimap(c);
}
if (!--vgacon_uni_pagedir[1])
con_free_unimap(c);
c->vc_uni_pagedir_loc = &c->vc_uni_pagedir;
con_set_default_unimap(c);
}
......
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