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[07/13] clocksource: arm_arch_timer: Discard unavailable timers correctly

Message ID 1411950226-21598-7-git-send-email-daniel.lezcano@linaro.org
State Accepted
Commit c387f07e6205cc13f57c1def5f885bf0a20e1c2d
Headers show

Commit Message

Daniel Lezcano Sept. 29, 2014, 12:23 a.m. UTC 
From: Sudeep Holla <sudeep.holla@arm.com>

Currently we wait until both cp15 and mem timers are probed if we
have both timer device nodes present in the device tree without
checking if the device is actually available. If one of the timer
device node present is disabled, the system locks up on the boot
as no timer gets registered.

This patch adds the check for the availability of the timer device
so that unavailable timers are discarded correctly. It also adds
the missing of_node_put.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/clocksource/arm_arch_timer.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)
diff mbox

Patch

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 5163ec1..7e267e3 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -616,17 +616,29 @@  static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
 	{},
 };
 
+static bool __init
+arch_timer_probed(int type, const struct of_device_id *matches)
+{
+	struct device_node *dn;
+	bool probed = false;
+
+	dn = of_find_matching_node(NULL, matches);
+	if (dn && of_device_is_available(dn) && (arch_timers_present & type))
+		probed = true;
+	of_node_put(dn);
+
+	return probed;
+}
+
 static void __init arch_timer_common_init(void)
 {
 	unsigned mask = ARCH_CP15_TIMER | ARCH_MEM_TIMER;
 
 	/* Wait until both nodes are probed if we have two timers */
 	if ((arch_timers_present & mask) != mask) {
-		if (of_find_matching_node(NULL, arch_timer_mem_of_match) &&
-				!(arch_timers_present & ARCH_MEM_TIMER))
+		if (!arch_timer_probed(ARCH_MEM_TIMER, arch_timer_mem_of_match))
 			return;
-		if (of_find_matching_node(NULL, arch_timer_of_match) &&
-				!(arch_timers_present & ARCH_CP15_TIMER))
+		if (!arch_timer_probed(ARCH_CP15_TIMER, arch_timer_of_match))
 			return;
 	}