Messages in this thread | | | Date | Fri, 24 Oct 2014 21:50:29 +0200 | From | Johan Hovold <> | Subject | Re: [PATCH] ARM: remove redundant irq disable at halt and restart |
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On Fri, Oct 24, 2014 at 02:42:50PM -0500, Felipe Balbi wrote: > On Fri, Oct 24, 2014 at 09:28:45PM +0200, Johan Hovold wrote: > > On Fri, Oct 24, 2014 at 02:21:11PM -0500, Felipe Balbi wrote: > > > On Fri, Oct 24, 2014 at 02:16:27PM -0500, Felipe Balbi wrote: > > > > On Fri, Oct 24, 2014 at 09:06:32PM +0200, Johan Hovold wrote: > > > > > Remove redundant local_irq_disable() at machine halt and restart. > > > > > > > > > > Since commit 44424c34049f ("ARM: 7803/1: Fix deadlock scenario with > > > > > smp_send_stop()") interrupts are disabled before stopping secondary > > > > > CPUs. > > > > > > > > Assuming this is correct, you should have: > > > > > > > > Fixes: 44424c3 (ARM: 7803/1: Fix deadlock scenario with smp_send_stop()) > > > > Cc: <stable@vger.kernel.org> # v3.12+ > > > > It's not a bug. Just a redundant disabling of already disabled > > interrupts, something which could possibly lead someone to believe that > > interrupts could be re-enabled by the power-off handler.
I meant re-enabled by arm_pm_restart().
> I didn't dig any of this out but I'll assume you did :-) So I withdraw > my comment ;-) > > > > > > diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c > > > > > index a35f6ebbd2c2..5663ab57cf07 100644 > > > > > --- a/arch/arm/kernel/process.c > > > > > +++ b/arch/arm/kernel/process.c > > > > > @@ -195,7 +195,6 @@ void machine_halt(void) > > > > > local_irq_disable(); > > > > > smp_send_stop(); > > > > > > > > > > - local_irq_disable(); > > > > > while (1); > > > > > } > > > > > > > > > > @@ -237,7 +236,6 @@ void machine_restart(char *cmd) > > > > > > > > > > /* Whoops - the platform was unable to reboot. Tell the user! */ > > > > > printk("Reboot failed -- System halted\n"); > > > > > - local_irq_disable(); > > > > > > > > ... but wouldn't this reintroduce the the buck which that commit fixed ? > > > > > > s/buck/bug :-) my fingers have a mind of their own, aparently. > > > > :) > > > > No, the interrupts would still be disabled. > > alright... so far I couldn't find where IRQs are disable before > machine_power_off() is called. Starting a do_poweroff(), couldn't find > it... Oh well, I'll keep digging.
It's done a few lines above in the same function. ;)
void machine_restart(char *cmd) { local_irq_disable(); ^^^ smp_send_stop();
arm_pm_restart(reboot_mode, cmd);
/* Give a grace period for failure to restart of 1s */ mdelay(1000);
/* Whoops - the platform was unable to reboot. Tell the user! */ printk("Reboot failed -- System halted\n"); local_irq_disable(); while (1); }
[ and similarly in machine_power_off(). ]
Johan
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