linux-kernel - Re: [RFC PATCH 06/10] spi: add support for ACPI reconfigure notifications

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20160405182454.GG1924@sirena.org.uk>
Date:	Tue, 5 Apr 2016 11:24:54 -0700
From:	Mark Brown <broonie@...nel.org>
To:	Octavian Purdila <octavian.purdila@...el.com>
Cc:	"Rafael J. Wysocki" <rafael@...nel.org>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Len Brown <lenb@...nel.org>,
	Matt Fleming <matt@...eblueprint.co.uk>,
	Wolfram Sang <wsa@...-dreams.de>,
	Joel Becker <jlbec@...lplan.org>,
	Christoph Hellwig <hch@....de>,
	"linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
	linux-efi@...r.kernel.org, linux-i2c <linux-i2c@...r.kernel.org>,
	linux-spi@...r.kernel.org, lkml <linux-kernel@...r.kernel.org>,
	Irina Tirdea <irina.tirdea@...el.com>
Subject: Re: [RFC PATCH 06/10] spi: add support for ACPI reconfigure
 notifications

On Mon, Apr 04, 2016 at 10:34:56PM +0300, Octavian Purdila wrote:
> On Mon, Apr 4, 2016 at 7:03 PM, Mark Brown <broonie@...nel.org> wrote:

> > Why is probe different to hotplug?  We don't need to do that in the
> > normal driver model.

> There might be some confusion with the term, I am referring to slave
> hotplug, not controller hotplug.

That's what I was talking about too.

> The way I see it, there are two logical operations: probe of a
> controller and the associated enumeration of the SPI slaves for that
> bus and "hotplug" of new SPI slaves and the enumeration of those
> particular slaves.

I don't see a distinction here.  The firmware finds some new slaves to
tell the framework about.  Quite why it decided to go looking shouldn't
matter.

> When a slave hotplug happens for device tree we get a device node
> notification and we can instantiate the SPI slave based on that info.
> In case of ACPI, (at this point) we get a global callback and in that
> callback we need to iterate through *all* controllers.

That's not really helping me understand why you need every bus to open
code enumeration twice?

Download attachment "signature.asc" of type "application/pgp-signature" (474 bytes)