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Geert Uytterhoeven 6e12db376b base: soc: Allow early registration of a single SoC device
Commit 1da1b3628d ("base: soc: Early register bus when needed")
added support for early registration of SoC devices from a
core_initcall().  However, some drivers need to check the SoC revision
from an early_initcall(), which is even earlier.

A specific example is the Renesas R-Car SYSC driver, which manages PM
Domains and thus needs to be initialized from an early_initcall.
Preproduction versions of the R-Car H3 SoC have an additional power
area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs
to check the exact SoC revision before instantiating a PM Domain for
that power area.

While registering the SoC bus and device, and using soc_device_match(),
from an early_initcall() do work, the "soc" directory and the "soc0"
file end up wrongly in the sysfs root, as the "bus" resp. "devices"
directories haven't been created yet.

To fix this, allow to register a single SoC device early on.
As long as the SoC bus isn't registered, soc_device_match() just
matches against this early device.
When the SoC bus is registered later, the early device is registered for
real.

Note that soc_device_register() returns NULL (no error, but also not a
valid pointer) when registering an early device.  Hence platform devices
cannot be instantiated as children of the "soc0" node representing an
early SoC device.  This should not be an issue, as that practice has
been deprecated for new platforms.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-29 21:43:26 +02:00
Documentation media fixes for v4.10-rc8 2017-02-14 06:29:21 -08:00
arch ARM: SoC fixes for v4.10 2017-02-18 17:38:09 -08:00
block cfq-iosched: don't call wbt_disable_default() with IRQs disabled 2017-02-16 08:02:06 -07:00
certs certs: Add a secondary system keyring that can be added to dynamically 2016-04-11 22:48:09 +01:00
crypto crypto: algif_aead - Fix kernel panic on list_del 2017-02-03 17:45:48 +08:00
drivers base: soc: Allow early registration of a single SoC device 2017-03-29 21:43:26 +02:00
firmware WHENCE: use https://linuxtv.org for LinuxTV URLs 2015-12-04 10:35:11 -02:00
fs vfs: fix uninitialized flags in splice_to_pipe() 2017-02-16 09:09:02 -08:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-16 08:37:18 -08:00
init kbuild: modversions: add infrastructure for emitting relative CRCs 2017-02-03 08:28:25 -08:00
ipc ipc/sem.c: fix incorrect sem_lock pairing 2017-01-10 18:31:55 -08:00
kernel Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-18 17:33:17 -08:00
lib rhashtable: Revert nested table changes. 2017-02-15 22:29:51 -05:00
mm mm/slub.c: fix random_seq offset destruction 2017-02-08 15:41:43 -08:00
net ipv6: release dst on error in ip6_dst_lookup_tail 2017-02-18 22:55:13 -05:00
samples bpf: introduce BPF_F_ALLOW_OVERRIDE flag 2017-02-12 21:52:19 -05:00
scripts kbuild: modversions: add infrastructure for emitting relative CRCs 2017-02-03 08:28:25 -08:00
security selinux: fix off-by-one in setprocattr 2017-02-08 19:09:53 +11:00
sound ALSA: hda - adding a new NV HDMI/DP codec ID in the driver 2017-02-09 08:57:47 +01:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-16 08:37:18 -08:00
usr kbuild: initramfs cleanup, set target from Kconfig 2017-01-05 09:40:16 -08:00
virt KVM/ARM updates for 4.10-rc4 2017-01-17 15:04:59 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap mailmap: add codeaurora.org names for nameless email commits 2017-01-10 18:31:55 -08:00
COPYING
CREDITS MAINTAINERS: Remove old e-mail address 2017-02-13 12:24:56 -05:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig
MAINTAINERS MAINTAINERS: Remove old e-mail address 2017-02-13 12:24:56 -05:00
Makefile Linux 4.10 2017-02-19 14:34:00 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.