• Russell King's avatar
    [PATCH] ARM: Generic Dynamic Tick Timer support for ARM, take 4 · 8749af68
    Russell King authored
    This patch adds support for Dynamic Tick Timer for ARM. Dynamic Tick is
    also known as VST (Variable Scheduling Timeouts).
    
    Dynamic Tick has been in use in the OMAP tree since last October.  The
    patch is not intrusive, and does not do anything unless CONFIG_NO_IDLE_HZ
    is defined.  This patch has the following fixed based on comments from
    RMK:
    - Time is updated before calling interrupt handlers.
    - Added new interrupt flag SA_TIMER to avoid duplicate timer interrupts
    - Moved struct dyn_tick_timer to time.h until we at some point probably
      have an arch independent dyn-tick.h
    - Cleaned up testing for DYN_TICK_ENABLED in irq.c
    
     I've cleaned up this patch to fix some remaining issues:
     - Call the timer tick handler with irqs disabled, as it would be from
       a normal interrupt
     - if we have a dyn_tick, we better implement all methods.
     - generic timer_dyn_reprogram() call, to be called before sleeping
     - added command line option - "dyntick=" to allow boot-time control
       of this feature
        -- rmk
    
    Signed-off-by: Tony Lindgren
    Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
    8749af68
irq.c 24.1 KB