linux-kernel - Re: [PATCH v2 04/18] clocksource: Add ARM System timer driver

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]

Message-ID: <CALszF6B1NV4193+az0Aep+C5R+=kn0a2HyyzU1HtfD_HnWCnRw@mail.gmail.com>
Date:	Mon, 9 Mar 2015 18:00:13 +0100
From:	Maxime Coquelin <mcoquelin.stm32@...il.com>
To:	Linus Walleij <linus.walleij@...aro.org>
Cc:	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>,
	Andreas Färber <afaerber@...e.de>,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	Rob Herring <robh+dt@...nel.org>,
	Philipp Zabel <p.zabel@...gutronix.de>,
	Jonathan Corbet <corbet@....net>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Russell King <linux@....linux.org.uk>,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jiri Slaby <jslaby@...e.cz>, Arnd Bergmann <arnd@...db.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"David S. Miller" <davem@...emloft.net>,
	Mauro Carvalho Chehab <mchehab@....samsung.com>,
	Joe Perches <joe@...ches.com>, Antti Palosaari <crope@....fi>,
	Tejun Heo <tj@...nel.org>, Will Deacon <will.deacon@....com>,
	Nikolay Borisov <Nikolay.Borisov@....com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Kees Cook <keescook@...omium.org>,
	Michal Marek <mmarek@...e.cz>,
	"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
	"linux-serial@...r.kernel.org" <linux-serial@...r.kernel.org>,
	"linux-arch@...r.kernel.org" <linux-arch@...r.kernel.org>,
	"linux-api@...r.kernel.org" <linux-api@...r.kernel.org>
Subject: Re: [PATCH v2 04/18] clocksource: Add ARM System timer driver

2015-03-09 16:50 GMT+01:00 Linus Walleij <linus.walleij@...aro.org>:
> On Fri, Feb 20, 2015 at 7:01 PM, Maxime Coquelin
> <mcoquelin.stm32@...il.com> wrote:
>
>> This patch adds clocksource support for ARMv7-M's System timer,
>> also known as SysTick.
>>
>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@...il.com>
> (...)
>> +       /* If no clock found, try to get clock-frequency property */
>> +       if (!rate) {
>> +               ret = of_property_read_u32(np, "clock-frequency", &rate);
>> +               if (ret)
>> +                       goto out_unmap;
>> +       }
>
> If this driver is only used for this one system, and if on this one system
> the clk subsystem will provide the clock rate, then there is no need
> to include this hackaround property.
>
> Alternatively there is no point including reading the frequency from
> the clk subsystem for this one system.
>
> So which one is it?

In the first version, the "clock-frequency" property handling was not here.
Rob Herring advised me to add its support, as it could be used by
simple systems not selecting CCF.

So, I don't have the name of a system where it could be useful, but I
think Rob's request make sense.

Note that I tested using the clock-frequency property before sending.

Best regards,
Maxime
>
> 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/