[PATCH] clock: initialize dummy clocksource statically

[Sascha Hauer]

Assigning the dummy clocksource in a initcall has the problem that
get_time_ns() crashes before that initcall is executed. This happens
when dmesg support is enabled in conjunction with CONFIG_DEBUG_INITCALLS.
In this case the dmesg code wants to have the timestamp of a log
message.
Solve this by setting the current clocksource to the dummy clock
statically and not at runtime. This way we always have a dummy
clock available.

Fixes:
commit 8972eb7ff17ad058a6c6018305bb912138ab0ca2
Author: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
Date:   Fri Mar 3 13:34:02 2017 +0100

    clocksource: move dummy clock source to init_clock

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 common/clock.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/common/clock.c b/common/clock.c
index 0d581c2c7e..f98176dd52 100644
--- a/common/clock.c
+++ b/common/clock.c
@@ -27,7 +27,6 @@
 #include <clock.h>
 #include <poller.h>
 
-static struct clocksource *current_clock;
 static uint64_t time_ns;
 
 /*
@@ -53,11 +52,7 @@ static struct clocksource dummy_cs = {
 	.priority = -1,
 };
 
-static int dummy_csrc_init(void)
-{
-	return init_clock(&dummy_cs);
-}
-pure_initcall(dummy_csrc_init);
+static struct clocksource *current_clock = &dummy_cs;
 
 static int dummy_csrc_warn(void)
 {
-- 
2.11.0