From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>,
Stephen Boyd <sboyd@codeaurora.org>,
Rajendra Nayak <rnayak@codeaurora.org>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, robdclark@gmail.com,
s.hauer@pengutronix.de, l.stach@pengutronix.de,
shawnguo@kernel.org, fabio.estevam@nxp.com, nm@ti.com,
xuwei5@hisilicon.com, robh+dt@kernel.org
Subject: Re: [PATCH V4 03/12] drivers: Add boot constraints core
Date: Wed, 13 Dec 2017 10:42:27 +0100 [thread overview]
Message-ID: <20171213094227.GC13194@kroah.com> (raw)
In-Reply-To: <2868a37e561cab91ba5495a1e14b9548c8e93c3e.1509284255.git.viresh.kumar@linaro.org>
On Sun, Oct 29, 2017 at 07:18:51PM +0530, Viresh Kumar wrote:
> Some devices are powered ON by the bootloader before the bootloader
> handovers control to Linux. It maybe important for those devices to keep
> working until the time a Linux device driver probes the device and
> reconfigure its resources.
>
> A typical example of that can be the LCD controller, which is used by
> the bootloaders to show image(s) while the platform is booting into
> Linux. The LCD controller can be using some resources, like clk,
> regulators, PM domain, etc, that are shared between several devices.
> These shared resources should be configured to satisfy need of all the
> users. If another device's (X) driver gets probed before the LCD
> controller driver in this case, then it may end up reconfiguring these
> resources to ranges satisfying the current users (only device X) and
> that can make the LCD screen unstable.
>
> This patch introduces the concept of boot-constraints, which will be set
> by the bootloaders and the kernel will satisfy them until the time
> driver for such a device is probed (successfully or unsuccessfully).
>
> The list of boot constraint types is empty for now, and will be
> incrementally updated by later patches.
>
> Only two routines are exposed by the boot constraints core for now:
I think we need some documentation somewhere on how to use this, right?
thanks,
greg k-h
next prev parent reply other threads:[~2017-12-13 9:42 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-29 13:48 [PATCH V4 00/12] drivers: Boot Constraints core Viresh Kumar
2017-10-29 13:48 ` [PATCH V4 01/12] of: platform: Add of_find_amba_device_by_node() Viresh Kumar
2017-10-29 13:48 ` [PATCH V4 02/12] of: platform: Make of_platform_bus_create() global Viresh Kumar
2017-10-29 13:48 ` [PATCH V4 03/12] drivers: Add boot constraints core Viresh Kumar
2017-12-13 9:42 ` Greg Kroah-Hartman
2017-12-13 9:59 ` Viresh Kumar
2017-12-13 9:42 ` Greg Kroah-Hartman [this message]
2017-12-13 10:00 ` Viresh Kumar
2017-10-29 13:48 ` [PATCH V4 04/12] boot_constraint: Add support for supply constraints Viresh Kumar
2017-12-13 9:48 ` Greg Kroah-Hartman
2017-10-29 13:48 ` [PATCH V4 05/12] boot_constraint: Add support for clk constraints Viresh Kumar
2017-12-13 9:48 ` Greg Kroah-Hartman
2017-10-29 13:48 ` [PATCH V4 06/12] boot_constraint: Add support for PM constraints Viresh Kumar
2017-12-13 9:48 ` Greg Kroah-Hartman
2017-10-29 13:48 ` [PATCH V4 07/12] boot_constraint: Add debugfs support Viresh Kumar
2017-10-29 15:09 ` Randy Dunlap
2017-10-30 3:37 ` Viresh Kumar
2017-10-30 3:43 ` Randy Dunlap
2017-12-13 9:50 ` Greg Kroah-Hartman
2017-10-29 13:48 ` [PATCH V4 08/12] boot_constraint: Manage deferrable constraints Viresh Kumar
2017-10-31 16:20 ` Rob Herring
2017-11-01 2:29 ` Viresh Kumar
2017-12-13 9:53 ` Greg Kroah-Hartman
2017-12-13 10:27 ` Viresh Kumar
2017-12-13 10:33 ` Russell King - ARM Linux
2017-12-13 14:39 ` Viresh Kumar
2017-10-29 13:48 ` [PATCH V4 09/12] boot_constraint: Add earlycon helper Viresh Kumar
2017-12-13 9:44 ` Greg Kroah-Hartman
2017-12-14 5:22 ` Viresh Kumar
2017-10-29 13:48 ` [PATCH V4 10/12] boot_constraint: Add support for Hisilicon platforms Viresh Kumar
2017-12-13 9:47 ` Greg Kroah-Hartman
2017-12-13 10:13 ` Viresh Kumar
2017-10-29 13:48 ` [PATCH V4 11/12] boot_constraint: Add support for IMX platform Viresh Kumar
2017-11-03 8:58 ` Sascha Hauer
2017-10-29 13:49 ` [PATCH V4 12/12] boot_constraint: Add Qualcomm display controller constraints Viresh Kumar
2017-10-30 22:07 ` [PATCH V4 00/12] drivers: Boot Constraints core Rob Herring
2017-10-31 10:01 ` Viresh Kumar
2017-11-28 4:18 ` Viresh Kumar
2017-12-13 9:55 ` Greg Kroah-Hartman
2017-12-13 10:27 ` Viresh Kumar
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