lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date:	Thu, 6 Feb 2014 11:28:24 +0900
From:	Alexandre Courbot <>
To:	Stephen Warren <>,
	Alexandre Courbot <>
CC:	Thierry Reding <>,
	Russell King <>,
	Olof Johansson <>,
	"" <>,
	Linux Kernel Mailing List <>
Subject: Re: [PATCH 5/5] ARM: tegra: cpuidle: use firmware call for power

On 02/06/2014 01:28 AM, Stephen Warren wrote:
> On 01/23/2014 12:39 AM, Alexandre Courbot wrote:
>> On Thu, Jan 23, 2014 at 5:45 AM, Stephen Warren <> wrote:
>>> On 01/21/2014 03:10 AM, Alexandre Courbot wrote:
>>>> Invoke the do_idle() firmware call before suspending a CPU so that the
>>>> underlying firmware (if any) can take necessary action.
>>>> diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c
>>>> @@ -45,6 +46,8 @@ static int tegra114_idle_power_down(struct cpuidle_device *dev,
>>>>        clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
>>>> +     call_firmware_op(do_idle);
>>>> +
>>>>        cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
>>>>        clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
>>> Don't you need to have the kernel also *not* do something when entering
>>> idle; doesn't the FW op replace some of the register writes that the
>>> kernel would otherwise be doing?
>> It seems like the operation is actually to inform the firmware that we
>> are going to suspend the CPU. Downstream kernel also uses it that way.
>> But you are right in that we should expect do_idle() to actually
>> perform the suspend operation. Maybe a prepare_idle() operation should
>> be added to the firmware interface for this purpose?
> That sounds like a reasonable change. Is it easy to plumb in?

I think so. Will post a v2 of this soon.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists