@@ -429,11 +429,19 @@ static void __init arch_counter_register(unsigned type)
u64 start_count;
/* Register the CP15 based counter if we have one */
- if (type & ARCH_CP15_TIMER)
+ if (type & ARCH_CP15_TIMER) {
arch_timer_read_counter = arch_counter_get_cntvct;
- else
+ } else {
arch_timer_read_counter = arch_counter_get_cntvct_mem;
+ /* If the clocksource name is "arch_sys_counter" the
+ * VDSO will attempt to read the CP15-based counter.
+ * Ensure this does not happen when CP15-based
+ * counter is not available.
+ */
+ clocksource_counter.name = "arch_mem_counter";
+ }
+
start_count = arch_timer_read_counter();
clocksource_register_hz(&clocksource_counter, arch_timer_rate);
cyclecounter.mult = clocksource_counter.mult;
This is a note to let you know that I have just added a patch titled clocksource: arm_arch_timer: Change clocksource name if CP15 unavailable to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt4. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 273e4b3c1b90b574cef9572860b6d455a5293275 Mon Sep 17 00:00:00 2001 From: Nathan Lynch <nathan_lynch@mentor.com> Date: Mon, 29 Sep 2014 01:50:06 +0200 Subject: clocksource: arm_arch_timer: Change clocksource name if CP15 unavailable commit 423bd69e69f565167ba14e2fe61df76c3c4a0d26 upstream. The arm and arm64 VDSOs need CP15 access to the architected counter. If this is unavailable (which is allowed by ARM v7), indicate this by changing the clocksource name to "arch_mem_counter" before registering the clocksource. Suggested by Stephen Boyd. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/clocksource/arm_arch_timer.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) -- 2.1.4