From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (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 C47453126A0 for ; Tue, 18 Nov 2025 09:13:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763457198; cv=none; b=cTEbkh/mwnk/svmtcQqNoUcChG1ULh/tBtYQJXYOH3XiOZiOVO9AHIl8NQRWxWrR5P7t+ZTuWq3ak9Q+J0GmlpgjFRmW+r6No3h9xrZCoUEAeZq63cudXtghfnRTrtpx0IEXBvB/CHZgW7V5SNPRuxoGmsinFBKdOD4v8lGqqno= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763457198; c=relaxed/simple; bh=JY8g9+Iv96I59y5ev4BmnnuzHSlvp11V8wDFWmv8Pbc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=B6JaEnRrv+yfWIevabq9tOD3WqEROMBLAsj7yZsvRoIAFI1zek3GnNguVzSM0Vq3lZGAzxtOt9f9IbcM3k5dlWTRuKuILPrbWifJHkUytte/ivOxIa2HDPtwiPsKlNCBdu5w15FtW2CxZnSTbPa60zBg/f9u2sz8a9adF+LBEDU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1vLHli-00056w-O1; Tue, 18 Nov 2025 10:12:58 +0100 Received: from pty.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::c5]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vLHlg-0013co-2R; Tue, 18 Nov 2025 10:12:56 +0100 Received: from ore by pty.whiteo.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1vLHlg-00A9WL-1z; Tue, 18 Nov 2025 10:12:56 +0100 Date: Tue, 18 Nov 2025 10:12:56 +0100 From: Oleksij Rempel To: "A. Sverdlin" Cc: Pengutronix Kernel Team , linux-iio@vger.kernel.org, Ahmad Fatoum , "Paul E . McKenney" , Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Jonathan Cameron , William Breathitt Gray Subject: Re: [PATCH] counter: interrupt-cnt: Drop IRQF_NO_THREAD flag Message-ID: References: <20251118083603.778626-1-alexander.sverdlin@siemens.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20251118083603.778626-1-alexander.sverdlin@siemens.com> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: stable@vger.kernel.org Hi Alexander, On Tue, Nov 18, 2025 at 09:35:48AM +0100, A. Sverdlin wrote: > From: Alexander Sverdlin > > An IRQ handler can either be IRQF_NO_THREAD or acquire spinlock_t, as > CONFIG_PROVE_RAW_LOCK_NESTING warns: > ============================= > [ BUG: Invalid wait context ] > 6.18.0-rc1+git... #1 > ----------------------------- > some-user-space-process/1251 is trying to lock: > (&counter->events_list_lock){....}-{3:3}, at: counter_push_event [counter] > other info that might help us debug this: > context-{2:2} > no locks held by some-user-space-process/.... > stack backtrace: > CPU: 0 UID: 0 PID: 1251 Comm: some-user-space-process 6.18.0-rc1+git... #1 PREEMPT > Call trace: > show_stack (C) > dump_stack_lvl > dump_stack > __lock_acquire > lock_acquire > _raw_spin_lock_irqsave > counter_push_event [counter] > interrupt_cnt_isr [interrupt_cnt] > __handle_irq_event_percpu > handle_irq_event > handle_simple_irq > handle_irq_desc > generic_handle_domain_irq > gpio_irq_handler > handle_irq_desc > generic_handle_domain_irq > gic_handle_irq > call_on_irq_stack > do_interrupt_handler > el0_interrupt > __el0_irq_handler_common > el0t_64_irq_handler > el0t_64_irq > > ... and Sebastian correctly points out. Remove IRQF_NO_THREAD as an > alternative to switching to raw_spinlock_t, because the latter would limit > all potential nested locks to raw_spinlock_t only. > > Cc: Sebastian Andrzej Siewior > Cc: stable@vger.kernel.org > Link: https://lore.kernel.org/all/20251117151314.xwLAZrWY@linutronix.de/ > Fixes: a55ebd47f21f ("counter: add IRQ or GPIO based counter") > Signed-off-by: Alexander Sverdlin > --- > drivers/counter/interrupt-cnt.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/counter/interrupt-cnt.c b/drivers/counter/interrupt-cnt.c > index 6c0c1d2d7027d..e6100b5fb082e 100644 > --- a/drivers/counter/interrupt-cnt.c > +++ b/drivers/counter/interrupt-cnt.c > @@ -229,8 +229,7 @@ static int interrupt_cnt_probe(struct platform_device *pdev) > > irq_set_status_flags(priv->irq, IRQ_NOAUTOEN); > ret = devm_request_irq(dev, priv->irq, interrupt_cnt_isr, > - IRQF_TRIGGER_RISING | IRQF_NO_THREAD, > - dev_name(dev), counter); > + IRQF_TRIGGER_RISING, dev_name(dev), counter); > if (ret) > return ret; > Hm, I guess it will break the requirement to handle at least 10kHz interrupts. May be we should move only counter_push_event() to the thread? or using delayed worker? Right now I do not have needed system for testing to come with better proposal. Best Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |