[PATCH 67/93] clocksource/drivers/nios2: Convert init function to return error

From: Daniel Lezcano
Date: Thu Jul 07 2016 - 04:20:33 EST


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.lezcano@xxxxxxxxxx>
---
arch/nios2/kernel/time.c | 65 +++++++++++++++++++++++++++++++++---------------
1 file changed, 45 insertions(+), 20 deletions(-)

diff --git a/arch/nios2/kernel/time.c b/arch/nios2/kernel/time.c
index e835dda..b75e40e 100644
--- a/arch/nios2/kernel/time.c
+++ b/arch/nios2/kernel/time.c
@@ -206,15 +206,21 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}

-static void __init nios2_timer_get_base_and_freq(struct device_node *np,
+static int __init nios2_timer_get_base_and_freq(struct device_node *np,
void __iomem **base, u32 *freq)
{
*base = of_iomap(np, 0);
- if (!*base)
- panic("Unable to map reg for %s\n", np->name);
+ if (!*base) {
+ pr_crit("Unable to map reg for %s\n", np->name);
+ return -ENXIO;
+ }
+
+ if (of_property_read_u32(np, "clock-frequency", freq)) {
+ pr_crit("Unable to get %s clock frequency\n", np->name);
+ return -EINVAL;
+ }

- if (of_property_read_u32(np, "clock-frequency", freq))
- panic("Unable to get %s clock frequency\n", np->name);
+ return 0;
}

static struct nios2_clockevent_dev nios2_ce = {
@@ -231,17 +237,21 @@ static struct nios2_clockevent_dev nios2_ce = {
},
};

-static __init void nios2_clockevent_init(struct device_node *timer)
+static __init int nios2_clockevent_init(struct device_node *timer)
{
void __iomem *iobase;
u32 freq;
- int irq;
+ int irq, ret;

- nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+ ret = nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+ if (ret)
+ return ret;

irq = irq_of_parse_and_map(timer, 0);
- if (!irq)
- panic("Unable to parse timer irq\n");
+ if (!irq) {
+ pr_crit("Unable to parse timer irq\n");
+ return -EINVAL;
+ }

nios2_ce.timer.base = iobase;
nios2_ce.timer.freq = freq;
@@ -253,25 +263,35 @@ static __init void nios2_clockevent_init(struct device_node *timer)
/* clear pending interrupt */
timer_writew(&nios2_ce.timer, 0, ALTERA_TIMER_STATUS_REG);

- if (request_irq(irq, timer_interrupt, IRQF_TIMER, timer->name,
- &nios2_ce.ced))
- panic("Unable to setup timer irq\n");
+ ret = request_irq(irq, timer_interrupt, IRQF_TIMER, timer->name,
+ &nios2_ce.ced);
+ if (ret) {
+ pr_crit("Unable to setup timer irq\n");
+ return ret;
+ }

clockevents_config_and_register(&nios2_ce.ced, freq, 1, ULONG_MAX);
+
+ return 0;
}

-static __init void nios2_clocksource_init(struct device_node *timer)
+static __init int nios2_clocksource_init(struct device_node *timer)
{
unsigned int ctrl;
void __iomem *iobase;
u32 freq;
+ int ret;

- nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+ ret = nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+ if (ret)
+ return ret;

nios2_cs.timer.base = iobase;
nios2_cs.timer.freq = freq;

- clocksource_register_hz(&nios2_cs.cs, freq);
+ ret = clocksource_register_hz(&nios2_cs.cs, freq);
+ if (ret)
+ return ret;

timer_writew(&nios2_cs.timer, USHRT_MAX, ALTERA_TIMER_PERIODL_REG);
timer_writew(&nios2_cs.timer, USHRT_MAX, ALTERA_TIMER_PERIODH_REG);
@@ -282,6 +302,8 @@ static __init void nios2_clocksource_init(struct device_node *timer)

/* Calibrate the delay loop directly */
lpj_fine = freq / HZ;
+
+ return 0;
}

/*
@@ -289,22 +311,25 @@ static __init void nios2_clocksource_init(struct device_node *timer)
* more instances, the second one gets used as clocksource and all
* others are unused.
*/
-static void __init nios2_time_init(struct device_node *timer)
+static int __init nios2_time_init(struct device_node *timer)
{
static int num_called;
+ int ret;

switch (num_called) {
case 0:
- nios2_clockevent_init(timer);
+ ret = nios2_clockevent_init(timer);
break;
case 1:
- nios2_clocksource_init(timer);
+ ret = nios2_clocksource_init(timer);
break;
default:
break;
}

num_called++;
+
+ return ret;
}

void read_persistent_clock(struct timespec *ts)
@@ -327,4 +352,4 @@ void __init time_init(void)
clocksource_probe();
}

-CLOCKSOURCE_OF_DECLARE(nios2_timer, ALTR_TIMER_COMPATIBLE, nios2_time_init);
+CLOCKSOURCE_OF_DECLARE_RET(nios2_timer, ALTR_TIMER_COMPATIBLE, nios2_time_init);
--
1.9.1