From: Ivaylo Dimitrov ivo.g.dimitrov.75@gmail.com
stable inclusion from stable-v6.6.2 commit 567d915092e3cbe25b78925d905cf4db1f5d3efb category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8IW7G
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
[ Upstream commit 12590d4d0e331d3cb9e6b3494515cd61c8a6624e ]
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: af04aa856e93 ("ARM: OMAP: Move dmtimer driver out of plat-omap to drivers under clocksource") Signed-off-by: Ivaylo Dimitrov ivo.g.dimitrov.75@gmail.com Reviewed-by: Tony Lindgren tony@atomide.com Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org Link: https://lore.kernel.org/r/1696312220-11550-1-git-send-email-ivo.g.dimitrov.7... Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/clocksource/timer-ti-dm.c | 36 ++++++++++++++++++++++++------- 1 file changed, 28 insertions(+), 8 deletions(-)
diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c index 09ab29cb7f64..5f60f6bd3386 100644 --- a/drivers/clocksource/timer-ti-dm.c +++ b/drivers/clocksource/timer-ti-dm.c @@ -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); }