[PATCH 54/93] clocksource/drivers/integrator-ap: Convert init function to return error

From: Daniel Lezcano
Date: Thu Jul 07 2016 - 04:04:26 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/timer-integrator-ap.c | 59 ++++++++++++++++++++-----------
1 file changed, 38 insertions(+), 21 deletions(-)

diff --git a/drivers/clocksource/timer-integrator-ap.c b/drivers/clocksource/timer-integrator-ap.c
index 3f59ac2..675face 100644
--- a/drivers/clocksource/timer-integrator-ap.c
+++ b/drivers/clocksource/timer-integrator-ap.c
@@ -36,11 +36,12 @@ static u64 notrace integrator_read_sched_clock(void)
return -readl(sched_clk_base + TIMER_VALUE);
}

-static void integrator_clocksource_init(unsigned long inrate,
- void __iomem *base)
+static int integrator_clocksource_init(unsigned long inrate,
+ void __iomem *base)
{
u32 ctrl = TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC;
unsigned long rate = inrate;
+ int ret;

if (rate >= 1500000) {
rate /= 16;
@@ -50,11 +51,15 @@ static void integrator_clocksource_init(unsigned long inrate,
writel(0xffff, base + TIMER_LOAD);
writel(ctrl, base + TIMER_CTRL);

- clocksource_mmio_init(base + TIMER_VALUE, "timer2",
- rate, 200, 16, clocksource_mmio_readl_down);
+ ret = clocksource_mmio_init(base + TIMER_VALUE, "timer2",
+ rate, 200, 16, clocksource_mmio_readl_down);
+ if (ret)
+ return ret;

sched_clk_base = base;
sched_clock_register(integrator_read_sched_clock, 16, rate);
+
+ return 0;
}

static unsigned long timer_reload;
@@ -138,11 +143,12 @@ static struct irqaction integrator_timer_irq = {
.dev_id = &integrator_clockevent,
};

-static void integrator_clockevent_init(unsigned long inrate,
- void __iomem *base, int irq)
+static int integrator_clockevent_init(unsigned long inrate,
+ void __iomem *base, int irq)
{
unsigned long rate = inrate;
unsigned int ctrl = 0;
+ int ret;

clkevt_base = base;
/* Calculate and program a divisor */
@@ -156,14 +162,18 @@ static void integrator_clockevent_init(unsigned long inrate,
timer_reload = rate / HZ;
writel(ctrl, clkevt_base + TIMER_CTRL);

- setup_irq(irq, &integrator_timer_irq);
+ ret = setup_irq(irq, &integrator_timer_irq);
+ if (ret)
+ return ret;
+
clockevents_config_and_register(&integrator_clockevent,
rate,
1,
0xffffU);
+ return 0;
}

-static void __init integrator_ap_timer_init_of(struct device_node *node)
+static int __init integrator_ap_timer_init_of(struct device_node *node)
{
const char *path;
void __iomem *base;
@@ -176,12 +186,12 @@ static void __init integrator_ap_timer_init_of(struct device_node *node)

base = of_io_request_and_map(node, 0, "integrator-timer");
if (IS_ERR(base))
- return;
+ return PTR_ERR(base);

clk = of_clk_get(node, 0);
if (IS_ERR(clk)) {
pr_err("No clock for %s\n", node->name);
- return;
+ return PTR_ERR(clk);
}
clk_prepare_enable(clk);
rate = clk_get_rate(clk);
@@ -189,31 +199,38 @@ static void __init integrator_ap_timer_init_of(struct device_node *node)

err = of_property_read_string(of_aliases,
"arm,timer-primary", &path);
- if (WARN_ON(err))
- return;
+ if (err) {
+ pr_warn("Failed to read property");
+ return err;
+ }
+
pri_node = of_find_node_by_path(path);
+
err = of_property_read_string(of_aliases,
"arm,timer-secondary", &path);
- if (WARN_ON(err))
- return;
+ if (err) {
+ pr_warn("Failed to read property");
+ return err;
+ }
+
+
sec_node = of_find_node_by_path(path);

- if (node == pri_node) {
+ if (node == pri_node)
/* The primary timer lacks IRQ, use as clocksource */
- integrator_clocksource_init(rate, base);
- return;
- }
+ return integrator_clocksource_init(rate, base);

if (node == sec_node) {
/* The secondary timer will drive the clock event */
irq = irq_of_parse_and_map(node, 0);
- integrator_clockevent_init(rate, base, irq);
- return;
+ return integrator_clockevent_init(rate, base, irq);
}

pr_info("Timer @%p unused\n", base);
clk_disable_unprepare(clk);
+
+ return 0;
}

-CLOCKSOURCE_OF_DECLARE(integrator_ap_timer, "arm,integrator-timer",
+CLOCKSOURCE_OF_DECLARE_RET(integrator_ap_timer, "arm,integrator-timer",
integrator_ap_timer_init_of);
--
1.9.1