From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934842AbdC3VBl (ORCPT ); Thu, 30 Mar 2017 17:01:41 -0400 Received: from mail-pg0-f53.google.com ([74.125.83.53]:36743 "EHLO mail-pg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934746AbdC3VBi (ORCPT ); Thu, 30 Mar 2017 17:01:38 -0400 From: John Stultz To: lkml Cc: Nicolai Stange , Ingo Molnar , Thomas Gleixner , Daniel Lezcano , Richard Cochran , Prarit Bhargava , Stephen Boyd , John Stultz Subject: [PATCH 3/9] clocksource: em_sti: Split clock prepare and enable steps Date: Thu, 30 Mar 2017 14:01:18 -0700 Message-Id: <1490907684-11186-4-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1490907684-11186-1-git-send-email-john.stultz@linaro.org> References: <1490907684-11186-1-git-send-email-john.stultz@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicolai Stange Currently, the em_sti driver prepares and enables the needed clock in em_sti_enable(), potentially called through its clockevent device's ->set_state_oneshot(). However, the clk_prepare() step may sleep whereas tick_program_event() and thus, ->set_state_oneshot(), can be called in atomic context. Split the clk_prepare_enable() in em_sti_enable() into two steps: - prepare the clock at device probing via clk_prepare() - and enable it in em_sti_enable() via clk_enable(). Slightly reorder resource initialization in em_sti_probe() in order to facilitate error handling in later patches. Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Daniel Lezcano Cc: Richard Cochran Cc: Prarit Bhargava Cc: Stephen Boyd Signed-off-by: Nicolai Stange Signed-off-by: John Stultz --- drivers/clocksource/em_sti.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/clocksource/em_sti.c b/drivers/clocksource/em_sti.c index aff87df..6c0955a 100644 --- a/drivers/clocksource/em_sti.c +++ b/drivers/clocksource/em_sti.c @@ -78,7 +78,7 @@ static int em_sti_enable(struct em_sti_priv *p) int ret; /* enable clock */ - ret = clk_prepare_enable(p->clk); + ret = clk_enable(p->clk); if (ret) { dev_err(&p->pdev->dev, "cannot enable clock\n"); return ret; @@ -107,7 +107,7 @@ static void em_sti_disable(struct em_sti_priv *p) em_sti_write(p, STI_INTENCLR, 3); /* stop clock */ - clk_disable_unprepare(p->clk); + clk_disable(p->clk); } static u64 em_sti_count(struct em_sti_priv *p) @@ -303,6 +303,7 @@ static int em_sti_probe(struct platform_device *pdev) struct em_sti_priv *p; struct resource *res; int irq; + int ret; p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL); if (p == NULL) @@ -323,6 +324,13 @@ static int em_sti_probe(struct platform_device *pdev) if (IS_ERR(p->base)) return PTR_ERR(p->base); + if (devm_request_irq(&pdev->dev, irq, em_sti_interrupt, + IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING, + dev_name(&pdev->dev), p)) { + dev_err(&pdev->dev, "failed to request low IRQ\n"); + return -ENOENT; + } + /* get hold of clock */ p->clk = devm_clk_get(&pdev->dev, "sclk"); if (IS_ERR(p->clk)) { @@ -330,11 +338,10 @@ static int em_sti_probe(struct platform_device *pdev) return PTR_ERR(p->clk); } - if (devm_request_irq(&pdev->dev, irq, em_sti_interrupt, - IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING, - dev_name(&pdev->dev), p)) { - dev_err(&pdev->dev, "failed to request low IRQ\n"); - return -ENOENT; + ret = clk_prepare(p->clk); + if (ret < 0) { + dev_err(&pdev->dev, "cannot prepare clock\n"); + return ret; } raw_spin_lock_init(&p->lock); -- 2.7.4