Commit 3814ae09 authored by Nicolai Stange's avatar Nicolai Stange Committed by John Stultz
Browse files

clocksource: em_sti: Split clock prepare and enable steps 



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.

Signed-off-by: default avatarNicolai Stange <nicstange@gmail.com>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent c3c0a20d

drivers/clocksource/em_sti.c

+14 −7
Original line number Diff line number Diff line
@@ -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);

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