Commit 12590d4d authored by Ivaylo Dimitrov's avatar Ivaylo Dimitrov Committed by Daniel Lezcano
Browse files

drivers/clocksource/timer-ti-dm: Don't call clk_get_rate() in stop function 



clk_get_rate() might sleep, and that prevents dm-timer based PWM from being
used from atomic context.

Fix that by getting fclk rate in probe() and using a notifier in case rate
changes.

Fixes: af04aa85 ("ARM: OMAP: Move dmtimer driver out of plat-omap to drivers under clocksource")
Signed-off-by: default avatarIvaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Reviewed-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1696312220-11550-1-git-send-email-ivo.g.dimitrov.75@gmail.com
parent 8051a993

drivers/clocksource/timer-ti-dm.c

+28 −8
Original line number Diff line number Diff line
@@ -140,6 +140,8 @@ struct dmtimer { 
	struct platform_device *pdev;

	struct list_head node;

	struct notifier_block nb;

	struct notifier_block fclk_nb;

	unsigned long fclk_rate;

};



static u32 omap_reserved_systimers;
@@ -253,8 +255,7 @@ static inline void __omap_dm_timer_enable_posted(struct dmtimer *timer) 
	timer->posted = OMAP_TIMER_POSTED;

}



static inline void __omap_dm_timer_stop(struct dmtimer *timer,

					unsigned long rate)

static inline void __omap_dm_timer_stop(struct dmtimer *timer)

{

	u32 l;
@@ -269,7 +270,7 @@ static inline void __omap_dm_timer_stop(struct dmtimer *timer, 
		 * Wait for functional clock period x 3.5 to make sure that

		 * timer is stopped

		 */

		udelay(3500000 / rate + 1);

		udelay(3500000 / timer->fclk_rate + 1);

#endif

	}
@@ -348,6 +349,21 @@ static int omap_timer_context_notifier(struct notifier_block *nb, 
	return NOTIFY_OK;

}



static int omap_timer_fclk_notifier(struct notifier_block *nb,

				    unsigned long event, void *data)

{

	struct clk_notifier_data *clk_data = data;

	struct dmtimer *timer = container_of(nb, struct dmtimer, fclk_nb);



	switch (event) {

	case POST_RATE_CHANGE:

		timer->fclk_rate = clk_data->new_rate;

		return NOTIFY_OK;

	default:

		return NOTIFY_DONE;

	}

}



static int omap_dm_timer_reset(struct dmtimer *timer)

{

	u32 l, timeout = 100000;
@@ -754,7 +770,6 @@ static int omap_dm_timer_stop(struct omap_dm_timer *cookie) 
{

	struct dmtimer *timer;

	struct device *dev;

	unsigned long rate = 0;



	timer = to_dmtimer(cookie);

	if (unlikely(!timer))
@@ -762,10 +777,7 @@ static int omap_dm_timer_stop(struct omap_dm_timer *cookie) 


	dev = &timer->pdev->dev;



	if (!timer->omap1)

		rate = clk_get_rate(timer->fclk);



	__omap_dm_timer_stop(timer, rate);

	__omap_dm_timer_stop(timer);



	pm_runtime_put_sync(dev);
@@ -1124,6 +1136,14 @@ static int omap_dm_timer_probe(struct platform_device *pdev) 
		timer->fclk = devm_clk_get(dev, "fck");

		if (IS_ERR(timer->fclk))

			return PTR_ERR(timer->fclk);



		timer->fclk_nb.notifier_call = omap_timer_fclk_notifier;

		ret = devm_clk_notifier_register(dev, timer->fclk,

						 &timer->fclk_nb);

		if (ret)

			return ret;



		timer->fclk_rate = clk_get_rate(timer->fclk);

	} else {

		timer->fclk = ERR_PTR(-ENODEV);

	}