diff mbox

[RFC,v4,09/13] ARM: msm: use remapped PPI interrupts for local timer

Message ID 4DDFFBC9.30002@codeaurora.org (mailing list archive)
State New, archived
Headers show

Commit Message

Stephen Boyd May 27, 2011, 7:30 p.m. UTC 
On 05/27/2011 09:27 AM, Marc Zyngier wrote:
> Use the normal interrupt scheme for the local timers by using
> a remapped PPI interrupt.
>
> MSM already had a very similar scheme, though still mixing both
> GIC-specific and generic APIs.
>
> Fixes and ideas courtesy of Stephen Boyd.
>
> Cc: David Brown <davidb@codeaurora.org>
> Cc: Daniel Walker <dwalker@fifo99.com>
> Cc: Bryan Huntsman <bryanh@codeaurora.org>

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

>  
> +static bool local_timer_inited;

Except this is unused if SMP=n. Here's a fix:

---8<----




---

But now I really want to know. Why can't we use system_state ==
SYSTEM_BOOTING? Perhaps I'm thinking ahead too much, but I'm concerned
that if we have more than two cores we're going to have to make a percpu
variable here just to avoid requesting the irq again. It would be
simpler to just accept the fact that we can't boot a secondary core for
the first time after kernel init due to the way the code is written.
If/when we decide to allow such a thing we can revisit this code and
make it into a percpu variable.

Or another idea is to pass a "first_boot" flag or something to
local_timer_setup() to indicate this is the first boot. Then we could
extend the percpu_clockevent variable in the localtimer core to have
this flag.

Either way it seems like something we should centralize.
diff mbox

Patch

diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c
index 186abdf..a242b89 100644
--- a/arch/arm/mach-msm/timer.c
+++ b/arch/arm/mach-msm/timer.c
@@ -84,7 +84,6 @@  enum {
 
 
 static struct msm_clock msm_clocks[];
-static bool local_timer_inited;
 
 static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
 {
@@ -259,6 +258,7 @@  int __cpuinit local_timer_setup(struct clock_event_device *evt)
 {
        struct msm_clock *clock = &msm_clocks[MSM_GLOBAL_TIMER];
        int res;
+       static bool local_timer_inited;
 
        /* Use existing clock_event for cpu 0 */
        if (!smp_processor_id())