[PATCHv2 0/4] clockevents: decouple broadcast mechanism from drivers

[sboyd@codeaurora.org (Stephen Boyd)]

On 01/09/13 06:46, Mark Rutland wrote:
> This is an updated version of the series I posted back in December:
> http://lists.infradead.org/pipermail/linux-arm-kernel/2012-December/137929.html
>
> Changes since v1:
> * Drop removal of guards in smp.c
> * Removed useless evt->evt_handler check in tick_receive_broadcast
> * Fix up tick_receive_broadcast when !GENERIC_CLOCKEVENTS_BROADCAST
> * Fix checkpatch issues (multi-line strings)
>
> Thanks go to Stephen Boyd and Santosh Shilimkar for their commments.
>
> In some SMP systems, cpu-local timers may stop delivering interrupts
> when in low power states, or not all CPUs may have local timers. To
> support these systems we have a mechanism for broadcasting timer ticks
> to other CPUs. This mechanism relies on the struct
> clock_event_device::broadcast function pointer, which is a
> driver-specific mechanism for broadcasting ticks to other CPUs.
>
> As the broadcast mechanism is architecture-specific, placing the
> broadcast function on struct clock_event_device ties each driver to a
> single architecture. Additionally the driver or architecture backend
> must handle the routing of broadcast ticks to the correct
> clock_event_device, leading to duplication of the list of active
> clock_event_devices.
>
> These patches introduce a generic mechanism for handling the receipt of
> timer broadcasts, and an optional architecture-specific broadcast
> function which allows drivers to be decoupled from a particular
> architecture will retaining support for timer tick broadcasts. These
> mechanisms are wired up for the arm port, and have been boot-tested on a
> pandaboard.
>

For the series:

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>

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