[PATCH V2 12/63] clocksource/drivers/armv7m_systick: Convert init function to return error

From: Daniel Lezcano
Date: Thu Jun 16 2016 - 17:44:46 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/armv7m_systick.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/clocksource/armv7m_systick.c b/drivers/clocksource/armv7m_systick.c
index addfd2c..2b55410 100644
--- a/drivers/clocksource/armv7m_systick.c
+++ b/drivers/clocksource/armv7m_systick.c
@@ -21,7 +21,7 @@

#define SYSTICK_LOAD_RELOAD_MASK 0x00FFFFFF

-static void __init system_timer_of_register(struct device_node *np)
+static int __init system_timer_of_register(struct device_node *np)
{
struct clk *clk = NULL;
void __iomem *base;
@@ -31,22 +31,26 @@ static void __init system_timer_of_register(struct device_node *np)
base = of_iomap(np, 0);
if (!base) {
pr_warn("system-timer: invalid base address\n");
- return;
+ return -ENXIO;
}

ret = of_property_read_u32(np, "clock-frequency", &rate);
if (ret) {
clk = of_clk_get(np, 0);
- if (IS_ERR(clk))
+ if (IS_ERR(clk)) {
+ ret = PTR_ERR(clk);
goto out_unmap;
+ }

ret = clk_prepare_enable(clk);
if (ret)
goto out_clk_put;

rate = clk_get_rate(clk);
- if (!rate)
+ if (!rate) {
+ ret = -EINVAL;
goto out_clk_disable;
+ }
}

writel_relaxed(SYSTICK_LOAD_RELOAD_MASK, base + SYST_RVR);
@@ -64,7 +68,7 @@ static void __init system_timer_of_register(struct device_node *np)

pr_info("ARM System timer initialized as clocksource\n");

- return;
+ return 0;

out_clk_disable:
clk_disable_unprepare(clk);
@@ -73,7 +77,9 @@ out_clk_put:
out_unmap:
iounmap(base);
pr_warn("ARM System timer register failed (%d)\n", ret);
+
+ return ret;
}

-CLOCKSOURCE_OF_DECLARE(arm_systick, "arm,armv7m-systick",
+CLOCKSOURCE_OF_DECLARE_RET(arm_systick, "arm,armv7m-systick",
system_timer_of_register);
--
1.9.1