[PATCH 23/92] clocksource/drivers/bcm2835_timer: Convert init function to return error

From: Daniel Lezcano
Date: Tue Jun 28 2016 - 06:47:45 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>
Acked-by: Eric Anholt <eric@xxxxxxxxxx>
---
drivers/clocksource/bcm2835_timer.c | 40 +++++++++++++++++++++++++------------
1 file changed, 27 insertions(+), 13 deletions(-)

diff --git a/drivers/clocksource/bcm2835_timer.c b/drivers/clocksource/bcm2835_timer.c
index 6f28229..2dcf896 100644
--- a/drivers/clocksource/bcm2835_timer.c
+++ b/drivers/clocksource/bcm2835_timer.c
@@ -80,19 +80,24 @@ static irqreturn_t bcm2835_time_interrupt(int irq, void *dev_id)
}
}

-static void __init bcm2835_timer_init(struct device_node *node)
+static int __init bcm2835_timer_init(struct device_node *node)
{
void __iomem *base;
u32 freq;
- int irq;
+ int irq, ret;
struct bcm2835_timer *timer;

base = of_iomap(node, 0);
- if (!base)
- panic("Can't remap registers");
+ if (!base) {
+ pr_err("Can't remap registers");
+ return -ENXIO;
+ }

- if (of_property_read_u32(node, "clock-frequency", &freq))
- panic("Can't read clock-frequency");
+ ret = of_property_read_u32(node, "clock-frequency", &freq);
+ if (ret) {
+ pr_err("Can't read clock-frequency");
+ return ret;
+ }

system_clock = base + REG_COUNTER_LO;
sched_clock_register(bcm2835_sched_read, 32, freq);
@@ -101,12 +106,16 @@ static void __init bcm2835_timer_init(struct device_node *node)
freq, 300, 32, clocksource_mmio_readl_up);

irq = irq_of_parse_and_map(node, DEFAULT_TIMER);
- if (irq <= 0)
- panic("Can't parse IRQ");
+ if (irq <= 0) {
+ pr_err("Can't parse IRQ");
+ return -EINVAL;
+ }

timer = kzalloc(sizeof(*timer), GFP_KERNEL);
- if (!timer)
- panic("Can't allocate timer struct\n");
+ if (!timer) {
+ pr_err("Can't allocate timer struct\n");
+ return -ENOMEM;
+ }

timer->control = base + REG_CONTROL;
timer->compare = base + REG_COMPARE(DEFAULT_TIMER);
@@ -121,12 +130,17 @@ static void __init bcm2835_timer_init(struct device_node *node)
timer->act.dev_id = timer;
timer->act.handler = bcm2835_time_interrupt;

- if (setup_irq(irq, &timer->act))
- panic("Can't set up timer IRQ\n");
+ ret = setup_irq(irq, &timer->act);
+ if (ret) {
+ pr_err("Can't set up timer IRQ\n");
+ return ret;
+ }

clockevents_config_and_register(&timer->evt, freq, 0xf, 0xffffffff);

pr_info("bcm2835: system timer (irq = %d)\n", irq);
+
+ return 0;
}
-CLOCKSOURCE_OF_DECLARE(bcm2835, "brcm,bcm2835-system-timer",
+CLOCKSOURCE_OF_DECLARE_RET(bcm2835, "brcm,bcm2835-system-timer",
bcm2835_timer_init);
--
1.9.1