From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752120AbbGRIMY (ORCPT <rfc822;w@1wt.eu>);
	Sat, 18 Jul 2015 04:12:24 -0400
Received: from www.linutronix.de ([62.245.132.108]:50387 "EHLO
	Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751437AbbGRIMT (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Sat, 18 Jul 2015 04:12:19 -0400
Date: Sat, 18 Jul 2015 10:12:03 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Alexandre Belloni <alexandre.belloni@free-electrons.com>
cc: Daniel Lezcano <daniel.lezcano@linaro.org>,
        Nicolas Ferre <nicolas.ferre@atmel.com>,
        Boris Brezillon <boris.brezillon@free-electrons.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        David Dueck <davidcdueck@googlemail.com>
Subject: Re: [PATCH 1/3] clocksource: atmel-st: Remove irq handler when clock
 event is unused
In-Reply-To: <1437161608-26782-2-git-send-email-alexandre.belloni@free-electrons.com>
Message-ID: <alpine.DEB.2.11.1507180942360.18576@nanos>
References: <1437161608-26782-1-git-send-email-alexandre.belloni@free-electrons.com> <1437161608-26782-2-git-send-email-alexandre.belloni@free-electrons.com>
User-Agent: Alpine 2.11 (DEB 23 2013-08-11)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-Linutronix-Spam-Score: -1.0
X-Linutronix-Spam-Level: -
X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required,  ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, 17 Jul 2015, Alexandre Belloni wrote:
> +static int atmel_st_request_irq(struct clock_event_device *dev)
> +{
> +	int ret;
> +
> +	if (clockevent_state_periodic(dev) || clockevent_state_oneshot(dev))
> +		return 0;
> +
> +	ret = request_irq(irq, at91rm9200_timer_interrupt,
> +			  IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
> +			  "at91_tick", regmap_st);
> +	if (ret) {
> +		pr_alert("Unable to setup IRQ\n");
> +		return ret;
> +	}
> +
>  	return 0;
>  }
>  
>  static int clkevt32k_set_oneshot(struct clock_event_device *dev)
>  {
> +	int ret;
> +
>  	clkdev32k_disable_and_flush_irq();
>  
>  	/*
>  	 * ALM for oneshot irqs, set by next_event()
>  	 * before 32 seconds have passed.
>  	 */
> +	ret = atmel_st_request_irq(dev);

You cannot call request_irq() from interrupt disabled context. It
works during early boot because might_sleep() is not active then, but
if that happens during normal runtime it wont work.

Thanks,

	tglx