[PATCH V2 18/63] clocksource/drivers/arm_global_timer: Convert init function to return error

From: Daniel Lezcano
Date: Thu Jun 16 2016 - 17:40:18 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>
---
drivers/clocksource/arm_global_timer.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
index 9df0d16..40104fc 100644
--- a/drivers/clocksource/arm_global_timer.c
+++ b/drivers/clocksource/arm_global_timer.c
@@ -238,7 +238,7 @@ static void __init gt_delay_timer_init(void)
register_current_timer_delay(&gt_delay_timer);
}

-static void __init gt_clocksource_init(void)
+static int __init gt_clocksource_init(void)
{
writel(0, gt_base + GT_CONTROL);
writel(0, gt_base + GT_COUNTER0);
@@ -249,7 +249,7 @@ static void __init gt_clocksource_init(void)
#ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
sched_clock_register(gt_sched_clock_read, 64, gt_clk_rate);
#endif
- clocksource_register_hz(&gt_clocksource, gt_clk_rate);
+ return clocksource_register_hz(&gt_clocksource, gt_clk_rate);
}

static int gt_cpu_notify(struct notifier_block *self, unsigned long action,
@@ -270,7 +270,7 @@ static struct notifier_block gt_cpu_nb = {
.notifier_call = gt_cpu_notify,
};

-static void __init global_timer_of_register(struct device_node *np)
+static int __init global_timer_of_register(struct device_node *np)
{
struct clk *gt_clk;
int err = 0;
@@ -283,19 +283,19 @@ static void __init global_timer_of_register(struct device_node *np)
if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9
&& (read_cpuid_id() & 0xf0000f) < 0x200000) {
pr_warn("global-timer: non support for this cpu version.\n");
- return;
+ return -ENOSYS;
}

gt_ppi = irq_of_parse_and_map(np, 0);
if (!gt_ppi) {
pr_warn("global-timer: unable to parse irq\n");
- return;
+ return -EINVAL;
}

gt_base = of_iomap(np, 0);
if (!gt_base) {
pr_warn("global-timer: invalid base address\n");
- return;
+ return -ENXIO;
}

gt_clk = of_clk_get(np, 0);
@@ -332,11 +332,17 @@ static void __init global_timer_of_register(struct device_node *np)
}

/* Immediately configure the timer on the boot CPU */
- gt_clocksource_init();
- gt_clockevents_init(this_cpu_ptr(gt_evt));
+ err = gt_clocksource_init();
+ if (err)
+ goto out_irq;
+
+ err = gt_clockevents_init(this_cpu_ptr(gt_evt));
+ if (err)
+ goto out_irq;
+
gt_delay_timer_init();

- return;
+ return 0;

out_irq:
free_percpu_irq(gt_ppi, gt_evt);
@@ -347,8 +353,10 @@ out_clk:
out_unmap:
iounmap(gt_base);
WARN(err, "ARM Global timer register failed (%d)\n", err);
+
+ return err;
}

/* Only tested on r2p2 and r3p0 */
-CLOCKSOURCE_OF_DECLARE(arm_gt, "arm,cortex-a9-global-timer",
+CLOCKSOURCE_OF_DECLARE_RET(arm_gt, "arm,cortex-a9-global-timer",
global_timer_of_register);
--
1.9.1