[Intel-gfx] [PATCH 18/21] fbcon: untangle fbcon_exit

Daniel Vetter
2022-01-31T21:07:25Z

There's a bunch of confusions going on here:
- The deferred fbcon setup notifier should only be cleaned up from
fb_console_exit(), to be symmetric with fb_console_init()
- We also need to make sure we don't race with the work, which means
temporarily dropping the console lock (or we can deadlock)
- That also means no point in clearing deferred_takeover, we are
unloading everything anyway.
- Finally rename fbcon_exit to fbcon_release_all and move it, since
that's what's it doing when being called from consw->con_deinit
through fbcon_deinit.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
drivers/video/fbdev/core/fbcon.c | 63 ++++++++++++++++----------------
1 file changed, 32 insertions(+), 31 deletions(-)

diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 5c14e24d14a1..22581952b4fd 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -185,7 +185,6 @@ static void fbcon_set_disp(struct fb_info *info, struct fb_var_screeninfo *var,
int unit);
static void fbcon_modechanged(struct fb_info *info);
static void fbcon_set_all_vcs(struct fb_info *info);
-static void fbcon_exit(void);

static struct device *fbcon_device;

@@ -1149,6 +1148,27 @@ static void fbcon_free_font(struct fbcon_display *p, bool freefont)

static void set_vc_hi_font(struct vc_data *vc, bool set);

+static void fbcon_release_all(void)
+{
+ struct fb_info *info;
+ int i, j, mapped;
+
+ for_each_registered_fb(i) {
+ mapped = 0;
+ info = registered_fb[i];
+
+ for (j = first_fb_vc; j <= last_fb_vc; j++) {
+ if (con2fb_map[j] == i) {
+ mapped = 1;
+ con2fb_map[j] = -1;
+ }
+ }
+
+ if (mapped)
+ fbcon_release(info);
+ }
+}
+
static void fbcon_deinit(struct vc_data *vc)
{
struct fbcon_display *p = &fb_display[vc->vc_num];
@@ -1188,7 +1208,7 @@ static void fbcon_deinit(struct vc_data *vc)
set_vc_hi_font(vc, false);

if (!con_is_bound(&fb_con))
- fbcon_exit();
+ fbcon_release_all();

if (vc->vc_num == logo_shown)
logo_shown = FBCON_LOGO_CANSHOW;
@@ -3316,34 +3336,6 @@ static void fbcon_start(void)
#endif
}

-static void fbcon_exit(void)
-{
- struct fb_info *info;
- int i, j, mapped;
-
-#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER
- if (deferred_takeover) {
- dummycon_unregister_output_notifier(&fbcon_output_nb);
- deferred_takeover = false;
- }
-#endif
-
- for_each_registered_fb(i) {
- mapped = 0;
- info = registered_fb[i];
-
- for (j = first_fb_vc; j <= last_fb_vc; j++) {
- if (con2fb_map[j] == i) {
- mapped = 1;
- con2fb_map[j] = -1;
- }
- }
-
- if (mapped)
- fbcon_release(info);
- }
-}
-
void __init fb_console_init(void)
{
int i;
@@ -3383,10 +3375,19 @@ static void __exit fbcon_deinit_device(void)

void __exit fb_console_exit(void)
{
+#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER
+ console_lock();
+ if (deferred_takeover)
+ dummycon_unregister_output_notifier(&fbcon_output_nb);
+ console_unlock();
+
+ cancel_work_sync(&fbcon_deferred_takeover_work);
+#endif
+
console_lock();
fbcon_deinit_device();
device_destroy(fb_class, MKDEV(0, 0));
- fbcon_exit();
+
do_unregister_con_driver(&fb_con);
console_unlock();
}
--
2.33.0