The init functions do not return any error. They behave as the following: - panic, thus leading to a kernel crash while another timer may work and make the system boot up correctly
or - print an error and let the caller unaware if the state of the system Change that by converting the init functions to return an error conforming to the CLOCKSOURCE_OF_RET prototype. Proper error handling (rollback, errno value) will be changed later case by case, thus this change just return back an error or success in the init function. Signed-off-by: Daniel Lezcano <daniel.lezc...@linaro.org> --- drivers/clocksource/cadence_ttc_timer.c | 82 +++++++++++++++++++-------------- 1 file changed, 48 insertions(+), 34 deletions(-) diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c index 9be6018..aa36cbf 100644 --- a/drivers/clocksource/cadence_ttc_timer.c +++ b/drivers/clocksource/cadence_ttc_timer.c @@ -322,22 +322,22 @@ static int ttc_rate_change_clocksource_cb(struct notifier_block *nb, return NOTIFY_DONE; } -static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base, +static int __init ttc_setup_clocksource(struct clk *clk, void __iomem *base, u32 timer_width) { struct ttc_timer_clocksource *ttccs; int err; ttccs = kzalloc(sizeof(*ttccs), GFP_KERNEL); - if (WARN_ON(!ttccs)) - return; + if (!ttccs) + return -ENOMEM; ttccs->ttc.clk = clk; err = clk_prepare_enable(ttccs->ttc.clk); - if (WARN_ON(err)) { + if (err) { kfree(ttccs); - return; + return err; } ttccs->ttc.freq = clk_get_rate(ttccs->ttc.clk); @@ -345,9 +345,13 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base, ttccs->ttc.clk_rate_change_nb.notifier_call = ttc_rate_change_clocksource_cb; ttccs->ttc.clk_rate_change_nb.next = NULL; - if (clk_notifier_register(ttccs->ttc.clk, - &ttccs->ttc.clk_rate_change_nb)) + + err = clk_notifier_register(ttccs->ttc.clk, + &ttccs->ttc.clk_rate_change_nb); + if (err) { pr_warn("Unable to register clock notifier.\n"); + return err; + } ttccs->ttc.base_addr = base; ttccs->cs.name = "ttc_clocksource"; @@ -368,14 +372,16 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base, ttccs->ttc.base_addr + TTC_CNT_CNTRL_OFFSET); err = clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE); - if (WARN_ON(err)) { + if (err) { kfree(ttccs); - return; + return err; } ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET; sched_clock_register(ttc_sched_clock_read, timer_width, ttccs->ttc.freq / PRESCALE); + + return 0; } static int ttc_rate_change_clockevent_cb(struct notifier_block *nb, @@ -401,30 +407,35 @@ static int ttc_rate_change_clockevent_cb(struct notifier_block *nb, } } -static void __init ttc_setup_clockevent(struct clk *clk, - void __iomem *base, u32 irq) +static int __init ttc_setup_clockevent(struct clk *clk, + void __iomem *base, u32 irq) { struct ttc_timer_clockevent *ttcce; int err; ttcce = kzalloc(sizeof(*ttcce), GFP_KERNEL); - if (WARN_ON(!ttcce)) - return; + if (!ttcce) + return -ENOMEM; ttcce->ttc.clk = clk; err = clk_prepare_enable(ttcce->ttc.clk); - if (WARN_ON(err)) { + if (err) { kfree(ttcce); - return; + return err; } ttcce->ttc.clk_rate_change_nb.notifier_call = ttc_rate_change_clockevent_cb; ttcce->ttc.clk_rate_change_nb.next = NULL; - if (clk_notifier_register(ttcce->ttc.clk, - &ttcce->ttc.clk_rate_change_nb)) + + err = clk_notifier_register(ttcce->ttc.clk, + &ttcce->ttc.clk_rate_change_nb); + if (err) { pr_warn("Unable to register clock notifier.\n"); + return err; + } + ttcce->ttc.freq = clk_get_rate(ttcce->ttc.clk); ttcce->ttc.base_addr = base; @@ -451,13 +462,15 @@ static void __init ttc_setup_clockevent(struct clk *clk, err = request_irq(irq, ttc_clock_event_interrupt, IRQF_TIMER, ttcce->ce.name, ttcce); - if (WARN_ON(err)) { + if (err) { kfree(ttcce); - return; + return err; } clockevents_config_and_register(&ttcce->ce, ttcce->ttc.freq / PRESCALE, 1, 0xfffe); + + return 0; } /** @@ -466,20 +479,14 @@ static void __init ttc_setup_clockevent(struct clk *clk, * Initializes the timer hardware and register the clock source and clock event * timers with Linux kernal timer framework */ -static void __init ttc_timer_init(struct device_node *timer) +static int __init ttc_timer_init(struct device_node *timer) { unsigned int irq; void __iomem *timer_baseaddr; struct clk *clk_cs, *clk_ce; - static int initialized; - int clksel; + int clksel, ret; u32 timer_width = 16; - if (initialized) - return; - - initialized = 1; - /* * Get the 1st Triple Timer Counter (TTC) block from the device tree * and use it. Note that the event timer uses the interrupt and it's the @@ -488,13 +495,13 @@ static void __init ttc_timer_init(struct device_node *timer) timer_baseaddr = of_iomap(timer, 0); if (!timer_baseaddr) { pr_err("ERROR: invalid timer base address\n"); - BUG(); + return -ENXIO; } irq = irq_of_parse_and_map(timer, 1); if (irq <= 0) { pr_err("ERROR: invalid interrupt number\n"); - BUG(); + return -EINVAL; } of_property_read_u32(timer, "timer-width", &timer_width); @@ -504,7 +511,7 @@ static void __init ttc_timer_init(struct device_node *timer) clk_cs = of_clk_get(timer, clksel); if (IS_ERR(clk_cs)) { pr_err("ERROR: timer input clock not found\n"); - BUG(); + return PTR_ERR(clk_cs); } clksel = readl_relaxed(timer_baseaddr + 4 + TTC_CLK_CNTRL_OFFSET); @@ -512,13 +519,20 @@ static void __init ttc_timer_init(struct device_node *timer) clk_ce = of_clk_get(timer, clksel); if (IS_ERR(clk_ce)) { pr_err("ERROR: timer input clock not found\n"); - BUG(); + return PTR_ERR(clk_cs); } - ttc_setup_clocksource(clk_cs, timer_baseaddr, timer_width); - ttc_setup_clockevent(clk_ce, timer_baseaddr + 4, irq); + ret = ttc_setup_clocksource(clk_cs, timer_baseaddr, timer_width); + if (ret) + return ret; + + ret = ttc_setup_clockevent(clk_ce, timer_baseaddr + 4, irq); + if (ret) + return ret; pr_info("%s #0 at %p, irq=%d\n", timer->name, timer_baseaddr, irq); + + return 0; } -CLOCKSOURCE_OF_DECLARE(ttc, "cdns,ttc", ttc_timer_init); +CLOCKSOURCE_OF_DECLARE_RET(ttc, "cdns,ttc", ttc_timer_init); -- 1.9.1