From 8f571bbfc621fd0826bbc7a8924c811f3a3167c9 Mon Sep 17 00:00:00 2001 From: Hans de Goede 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 --- 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) @@ -3611,10 +3626,8 @@ 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]); - } + /* We may get called in atomic context */ + schedule_work(&fbcon_deferred_takeover_work); return NOTIFY_OK; } -- 2.18.0