linux-kernel - Re: [RFC][PATCH] rtc: rtc-pl031: Set wakeup flag prior to registering rtcdev

lists.openwall.net		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] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 18 Sep 2013 13:30:49 +0200
From:	Linus Walleij <linus.walleij@...aro.org>
To:	John Stultz <john.stultz@...aro.org>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Alessandro Zummo <a.zummo@...ertech.it>,
	"Jon Medhurst (Tixy)" <tixy@...aro.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [RFC][PATCH] rtc: rtc-pl031: Set wakeup flag prior to registering rtcdev

On Tue, Sep 17, 2013 at 8:29 PM, John Stultz <john.stultz@...aro.org> wrote:

> In some recent testing, I noticed the CLOCK_REALTIME_ALARM clockid
> wasn't functioning on my vexpress qemu environment. Looking into it
> I noticed the pl031 rtc driver doesn't set the wakeup flag on the
> device until after registering the device with the RTC subsystem.
>
> This causes the alarmtimer subsystem to not see the pl031 driver
> as a valid backing device, and that resuls in alarm clockids
> getting ENOTSUPP errors.
>
> Thus be sure to set the wakeup flag on the device prior to
> registering the rtcdev so the pl031 rtc driver can be used as
> the backing alarmtimer device.
>
> Let me know if you have any feedback or objections to this.
> If it looks ok, I'll queue it for 3.13. I suspect there
> may be other RTC drivers with the same problem.
>
> Cc: Linus Walleij <linus.walleij@...aro.org>
> Cc: Alessandro Zummo <a.zummo@...ertech.it>
> Cc: "Jon Medhurst (Tixy)" <tixy@...aro.org>
> Cc: linux-arm-kernel@...ts.infradead.org
> Signed-off-by: John Stultz <john.stultz@...aro.org>

Makes perfect sense. I have only tested the driver from regular
userspace using ioctl()s. Is these a simple way to test
an alarmtimer on a barebones system?

Acked-by: Linus Walleij <linus.walleij@...aro.org>

Are you sure this should not be for -rc:s and stable?

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