From: John Ogness Date: Fri, 21 Nov 2025 10:20:00 +0000 (+0106) Subject: printk: Avoid irq_work for printk_deferred() on suspend X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=66e7c1e0ee08cfb6db64f8f3f6e5a3cc930145c8;p=thirdparty%2Flinux.git printk: Avoid irq_work for printk_deferred() on suspend With commit ("printk: Avoid scheduling irq_work on suspend") the implementation of printk_get_console_flush_type() was modified to avoid offloading when irq_work should be blocked during suspend. Since printk uses the returned flush type to determine what flushing methods are used, this was thought to be sufficient for avoiding irq_work usage during the suspend phase. However, vprintk_emit() implements a hack to support printk_deferred(). In this hack, the returned flush type is adjusted to make sure no legacy direct printing occurs when printk_deferred() was used. Because of this hack, the legacy offloading flushing method can still be used, causing irq_work to be queued when it should not be. Adjust the vprintk_emit() hack to also consider @console_irqwork_blocked so that legacy offloading will not be chosen when irq_work should be blocked. Link: https://lore.kernel.org/lkml/87fra90xv4.fsf@jogness.linutronix.de Signed-off-by: John Ogness Fixes: 26873e3e7f0c ("printk: Avoid scheduling irq_work on suspend") Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek --- diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index b1c0d35cf3ca..c27fc7fc64eb 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2393,7 +2393,7 @@ asmlinkage int vprintk_emit(int facility, int level, /* If called from the scheduler, we can not call up(). */ if (level == LOGLEVEL_SCHED) { level = LOGLEVEL_DEFAULT; - ft.legacy_offload |= ft.legacy_direct; + ft.legacy_offload |= ft.legacy_direct && !console_irqwork_blocked; ft.legacy_direct = false; }