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From 8f571bbfc621fd0826bbc7a8924c811f3a3167c9 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Mon, 6 Aug 2018 16:32:27 +0200
Subject: [PATCH] fbcon: Do not takeover the console from atomic context
Taking over the console involves allocating mem with GFP_KERNEL, talking
to drm drivers, etc. So this should not be done from an atomic context.
But the console-output trigger deferred console takeover may happen from an
atomic context, which leads to "BUG: sleeping function called from invalid
context" errors.
This commit fixes these errors by doing the deferred takeover from a
workqueue when the notifier runs from an atomic context.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/video/fbdev/core/fbcon.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index a3fd510..f812891 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -3596,7 +3596,22 @@ static int fbcon_init_device(void)
}
#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER
+static void fbcon_register_existing_fbs(struct work_struct *work)
+{
+ int i;
+
+ console_lock();
+
+ for (i = 0; i < FB_MAX; i++) {
+ if (registered_fb[i])
+ fbcon_fb_registered(registered_fb[i]);
+ }
+
+ console_unlock();
+}
+
static struct notifier_block fbcon_output_nb;
+static DECLARE_WORK(fbcon_deferred_takeover_work, fbcon_register_existing_fbs);
static int fbcon_output_notifier(struct notifier_block *nb,
unsigned long action, void *data)
@@ -3611,9 +3626,13 @@ static int fbcon_output_notifier(struct notifier_block *nb,
deferred_takeover = false;
logo_shown = FBCON_LOGO_DONTSHOW;
- for (i = 0; i < FB_MAX; i++) {
- if (registered_fb[i])
- fbcon_fb_registered(registered_fb[i]);
+ if (in_atomic() || irqs_disabled()) {
+ schedule_work(&fbcon_deferred_takeover_work);
+ } else {
+ for (i = 0; i < FB_MAX; i++) {
+ if (registered_fb[i])
+ fbcon_fb_registered(registered_fb[i]);
+ }
}
return NOTIFY_OK;
--
2.18.0
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