This is a note to let you know that I have just added a patch titled clocksource: vf_pit_timer: use complement for sched_clock reading to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ >From 1a35c24db888b0a2b48933680ed8fd490bddf680 Mon Sep 17 00:00:00 2001 From: Stefan Agner <stefan@xxxxxxxx> Date: Wed, 5 Mar 2014 23:11:08 +0100 Subject: clocksource: vf_pit_timer: use complement for sched_clock reading commit 224aa3ed45c8735ae02bb2ecca002409fa6aa772 upstream. Vybrids PIT register is monitonic decreasing. However, sched_clock reading needs to be monitonic increasing. Use bitwise not to get the complement of the clock register. This fixes the clock going backward. Also, the clock now starts at 0 since we load the register with the maximum value at start. Signed-off-by: Stefan Agner <stefan@xxxxxxxx> Acked-by: Shawn Guo <shawn.guo@xxxxxxxxxx> Cc: daniel.lezcano@xxxxxxxxxx Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Cc: linux@xxxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/d25af915993aec1b486be653eb86f748ddef54fe.1394057313.git.stefan@xxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx> --- drivers/clocksource/vf_pit_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clocksource/vf_pit_timer.c b/drivers/clocksource/vf_pit_timer.c index 587e020..e559095 100644 --- a/drivers/clocksource/vf_pit_timer.c +++ b/drivers/clocksource/vf_pit_timer.c @@ -54,7 +54,7 @@ static inline void pit_irq_acknowledge(void) static unsigned int pit_read_sched_clock(void) { - return __raw_readl(clksrc_base + PITCVAL); + return ~__raw_readl(clksrc_base + PITCVAL); } static int __init pit_clocksource_init(unsigned long rate) -- 1.9.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-arm-kernel