From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DE5755A987A; Tue, 8 Sep 2026 20:07:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788898052; cv=none; b=ok5GYNy44kCuPcmTDZlH1M9cM4Elk9LD+VabmJgZoJevsMIgPUN4e1gjQW2Z7zinqgmZFRHKmstktTRrel/wuIWAbGJeIAxLeGVoc5kRlloEc+COvKltFelDr3EHSHSixyMJnNIKKwT7GgUJrMJOA4XQgsnqNv8uOlI8cy5PYUI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788898052; c=relaxed/simple; bh=+58J6D3CE4XJKlOjtrnHo4Q/C2s+g1wtC9m2MXhx4vs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=TbjNH00AxIpZ4OE2wrUlvIJQPAhSeYHKZNwFIoo4KwnX7rKm8979gsh6upAZmg97xTkHzXDRXg3ELZzd4d/gEQMXpcwilVEauxn1MssysD01ZmDkx39dF1O7m7XQVPWoGfOzT/0cKe1Mfj/jGQ2H0jbh2z9TgfWXck2RSy6fbTE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EGTJ7QR7; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EGTJ7QR7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 340F11F00A3D; Tue, 8 Sep 2026 20:07:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788898049; bh=iJOWJWZvof6Aiu8tr3s25l3nk9WBufyE2g4zQc4CtfM=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=EGTJ7QR7Lt3NiLz+E6t3GFiwCY6WeF0N11n7PdlGiOiLrHZX4r4GptoeRIddmZ5ba a6blWerESKctCBmyVJ5tMc6GzZdW1+FEk+3SCFjPruF8n1+bicbrOdbdOVNSf8wxOH z160qZ1Ep/t9PsutCIQxDQMrY19tWAkzMVJH1hbXzDArdjSG/Xn8kkunk0sEIDy/+j bikHWmyYmGvzzlub4kNyvR7T/3xdLbvCgWSUfWDAFqLnUlQhFGGDGiCgv/duU+doRn bAoYE1++RXmodzQxuvH2Pq3+Vf2xVA1nuyWb9ucleVLCeCt2Fd5pOPfEuedQwP8MgW d9f/kiDOTZnnQ== From: Thomas Gleixner To: Zhu Ling Cc: Zhu Ling , "Rafael J. Wysocki" , Radu Rendec , Pavel Machek , Len Brown , Greg Kroah-Hartman , Danilo Krummrich , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, driver-core@lists.linux.dev Subject: Re: [PATCH] genirq/PM: Re-enable chained interrupts after hibernation In-Reply-To: References: Date: Tue, 08 Sep 2026 22:07:25 +0200 Message-ID: <87mrtr1p8i.ffs@fw13> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Sat, Sep 05 2026 at 23:27, Zhu Ling wrote: > Chained interrupts remain enabled across suspend because they can be part > of a wakeup path. Consequently, suspend_device_irq() does not set > IRQS_SUSPENDED for them, and they do not have IRQF_FORCE_RESUME accounting. > > After restoring a hibernation image, the interrupt controller can have a > chained parent interrupt masked while the restored descriptor still marks > it started and enabled. For example, the restore kernel may initialize the > controller without probing the driver that installs the chained handler. > resume_irq() skips the parent in this state, leaving interrupts from the > devices below it blocked. > > Pass the hibernation restore context from dpm_resume_noirq() to the IRQ PM > code and force active chained interrupts through the existing force-resume > path. Set the disabled and masked state before enabling the interrupt so > that cached descriptor state cannot suppress the irqchip callback. Calling > irq_startup() alone on an already started and enabled interrupt can skip > the hardware access when the descriptor also records it as unmasked. > > Leave disabled and unstarted chained interrupts alone. Keep the existing > behavior for ordinary resume, hibernation thaw and recovery, and the early > syscore resume pass. > > Fixes: 0a0c5168df27 ("PM: Introduce functions for suspending and resuming device interrupts") This fixes nothing than a theoretical problem hallucinated by a LLM and we don't fix hallucinations. If that would be a real world problem then this change would cure the symptom and not the root cause. Thanks, tglx