Re: [PATCHv2 0/4] clockevents: decouple broadcast mechanism fromdrivers

From: Stephen Boyd
Date: Wed Jan 09 2013 - 15:46:09 EST


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@xxxxxxxxxxxxxx>

--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/