On 2015?01?05? 15:55, Suthikulpanit, Suravee wrote:

On 1/4/15, 04:55, "Hanjun Guo" [off-list ref] wrote:

quoted

Using the information presented by GTDT to initialize the arch
timer (not memory-mapped).

Originally-by: Amit Daniel Kachhap [off-list ref]
Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: Hanjun Guo <redacted>
---
arch/arm64/kernel/time.c             |   7 ++
drivers/clocksource/arm_arch_timer.c | 132
++++++++++++++++++++++++++++-------
include/linux/clocksource.h          |   6 ++
3 files changed, 118 insertions(+), 27 deletions(-)

[...]

quoted

+static void __init arch_timer_of_init(struct device_node *np)
+{
+	int i;
+
+	if (arch_timers_present & ARCH_CP15_TIMER) {
+		pr_warn("arch_timer: multiple nodes in dt, skipping\n");
+		return;
+	}
+
+	arch_timers_present |= ARCH_CP15_TIMER;
+	for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
+		arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
+
+	arch_timer_detect_rate(NULL, np);
+
+	arch_timer_c3stop = !of_property_read_bool(np, "always-on");
+
+	/*
+	 * If we cannot rely on firmware initializing the timer registers then
+	 * we should use the physical timers instead.
+	 */
+	if (IS_ENABLED(CONFIG_ARM) &&
+	    of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
+			arch_timer_use_virtual = false;
+
+	arch_timer_init();
+}
+CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer",
arch_timer_of_init);
+CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer",
arch_timer_of_init);

Hanjun,

FYI, it seems that the tree that you have rebased the patch series has an
issue determining clocksource in ARM64 introduced by this commit.

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=0
b46b8a718c6e90910a1b1b0fe797be3c167e186

Here is the fix from Catalin that already went upstream:

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drive
rs/clocksource/arm_arch_timer.c?id=d6ad36913083d683aad4e02e53580c995f1a6ede

This bug fix patch was merged in Dec 30 by Linus, which is the date
after 3.19-rc2 released :)

Thanks
Hanjun