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Kai-Heng Feng bacd861452 ALSA: hda: Allow HDA to be runtime suspended when dGPU is not bound to a driver
Nvidia proprietary driver doesn't support runtime power management, so
when a user only wants to use the integrated GPU, it's a common practice
to let dGPU not to bind any driver, and let its upstream port to be
runtime suspended. At the end of runtime suspension the port uses
platform power management to disable power through _OFF method of power
resource, which is listed by _PR3.

After commit b516ea586d ("PCI: Enable NVIDIA HDA controllers"), when
the dGPU comes with an HDA function, the HDA won't be suspended if the
dGPU is unbound, so the power resource can't be turned off by its
upstream port driver.

Commit 37a3a98ef6 ("ALSA: hda - Enable runtime PM only for
discrete GPU") only allows HDA to be runtime suspended once GPU is
bound, to keep APU's HDA working.

However, HDA on dGPU isn't that useful if dGPU is not bound to any
driver.  So let's relax the runtime suspend requirement for dGPU's HDA
function, to disable the power source to save lots of power.

BugLink: https://bugs.launchpad.net/bugs/1840835
Fixes: b516ea586d ("PCI: Enable NVIDIA HDA controllers")
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20191018073848.14590-2-kai.heng.feng@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-10-21 15:14:07 +02:00
Documentation Kbuild fixes for v5.4 2019-10-05 12:56:59 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch ARM: SoC fixes 2019-10-05 17:18:43 -07:00
block block: sed-opal: fix sparse warning: convert __be64 data 2019-10-03 14:21:32 -06:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
drivers PCI: Add a helper to check Power Resource Requirements _PR3 existence 2019-10-21 15:13:18 +02:00
fs elf: don't use MAP_FIXED_NOREPLACE for elf executable mappings 2019-10-06 13:53:27 -07:00
include PCI: Add a helper to check Power Resource Requirements _PR3 existence 2019-10-21 15:13:18 +02:00
init Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
ipc ipc/sem.c: convert to use built-in RCU list checking 2019-09-25 17:51:41 -07:00
kernel dma-mapping regression fix for 5.4-rc2 2019-10-06 11:10:15 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-05 08:50:15 -07:00
mm Merge branch 'hugepage-fallbacks' (hugepatch patches from David Rientjes) 2019-09-28 14:26:47 -07:00
net nfc: fix memory leak in llcp_sock_bind() 2019-10-04 18:31:36 -07:00
samples rpmsg updates for v5.4 2019-09-22 10:58:15 -07:00
scripts scripts/setlocalversion: clear local variable to make it work for sh 2019-10-05 15:29:49 +09:00
security integrity: remove pointless subdir-$(CONFIG_...) 2019-10-05 15:29:49 +09:00
sound ALSA: hda: Allow HDA to be runtime suspended when dGPU is not bound to a driver 2019-10-21 15:14:07 +02:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-05 08:50:15 -07:00
usr kbuild: update compile-test header list for v5.4-rc2 2019-10-05 15:29:49 +09:00
virt KVM/arm fixes for 5.4, take #1 2019-10-03 12:08:50 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-09-18 12:34:53 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS CREDITS: Update email address 2019-09-13 17:21:38 +03:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS kgdb patches for 5.4-rc2 2019-10-03 11:17:57 -07:00
Makefile Linux 5.4-rc2 2019-10-06 14:27:30 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

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.