linux-kernel - Re: [PATCH v4 4/4] ARM: mvebu: Armada 385 GP: Add regulators to the SATA port

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:	Fri, 16 Jan 2015 20:13:36 +0100
From:	Hans de Goede <hdegoede@...hat.com>
To:	Mark Brown <broonie@...nel.org>,
	Gregory CLEMENT <gregory.clement@...e-electrons.com>
CC:	Tejun Heo <tj@...nel.org>, linux-ide@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Antoine Ténart 
	<antoine.tenart@...e-electrons.com>,
	Liam Girdwood <lgirdwood@...il.com>,
	Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>,
	Ezequiel Garcia <ezequiel.garcia@...e-electrons.com>,
	Maxime Ripard <maxime.ripard@...e-electrons.com>,
	Boris BREZILLON <boris.brezillon@...e-electrons.com>,
	Jason Cooper <jason@...edaemon.net>,
	Andrew Lunn <andrew@...n.ch>,
	Sebastian Hesselbarth <sebastian.hesselbarth@...il.com>,
	linux-arm-kernel@...ts.infradead.org,
	Lior Amsalem <alior@...vell.com>,
	Tawfik Bayouk <tawfik@...vell.com>,
	Nadav Haklai <nadavh@...vell.com>,
	Mark Rutland <mark.rutland@....com>, devicetree@...r.kernel.org
Subject: Re: [PATCH v4 4/4] ARM: mvebu: Armada 385 GP: Add regulators to the
 SATA port

Hi,

On 16-01-15 16:34, Mark Brown wrote:
> On Fri, Jan 16, 2015 at 03:27:00PM +0100, Gregory CLEMENT wrote:
>> On 16/01/2015 13:37, Mark Brown wrote:
>
>>> regulator-always-on is a bit fuzzy for suspend, if the regulator has
>>> suspend control it'll kick in - it's really about the Linux refcounting
>>> while it's running.  What's more concerning here is that the quick
>>> sample of the regulators flagged as always on like the above that I
>>> looked at in the patch don't seem to have any enable control in the DT
>>> so this will have absolutely no effect.
>
>> Actually the reg_sata[0-4] are controlled by gpio, so there is a mean
>> to enable/disable them. For the reg_5v_sata[0-4] and reg_12v_sata[0-4]
>> they depend on their respective reg_sata and I just propagated the
>> regulator-always-on, this was maybe a mistake.
>
> It certainly makes everything confusing if you have control related
> stuff on regulators that are not directly controllable.
>
>>>> It is probably a good idea to use regulator-boot-on and
>>>> then test things this way, and if that works use
>>>> regulator-boot-on.
>
>>> No, it's unlikely that boot-on makes sense here - it's there for cases
>>> where we can't read back the hardware state at power on.  Generally
>>> drivers should work regardless of the initial state of the regulator
>>> (and modular drivers will actually break if they try to rely on boot-on
>>> since we clean up unused regulators at boot).
>
>> As pointed by Hans my concern here was be sure that during boot the disk
>> are not power off. In this case which property would be accurate?
>
> None, the core won't do anything with the regulator until the end of
> init anyway.

That us simply not true, see my other mail gpio enabled regulators will
be turned off *at register time* unless they have regulator-boot-on set.

Regards,

Hans

--
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/