linux/drivers
Matthew Garrett 3c076351c4 PCI: Rework ASPM disable code
Right now we forcibly clear ASPM state on all devices if the BIOS indicates
that the feature isn't supported. Based on the Microsoft presentation
"PCI Express In Depth for Windows Vista and Beyond", I'm starting to think
that this may be an error. The implication is that unless the platform
grants full control via _OSC, Windows will not touch any PCIe features -
including ASPM. In that case clearing ASPM state would be an error unless
the platform has granted us that control.

This patch reworks the ASPM disabling code such that the actual clearing
of state is triggered by a successful handoff of PCIe control to the OS.
The general ASPM code undergoes some changes in order to ensure that the
ability to clear the bits isn't overridden by ASPM having already been
disabled. Further, this theoretically now allows for situations where
only a subset of PCIe roots hand over control, leaving the others in the
BIOS state.

It's difficult to know for sure that this is the right thing to do -
there's zero public documentation on the interaction between all of these
components. But enough vendors enable ASPM on platforms and then set this
bit that it seems likely that they're expecting the OS to leave them alone.

Measured to save around 5W on an idle Thinkpad X220.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-12-05 10:21:45 -08:00
..
accessibility
acpi PCI: Rework ASPM disable code 2011-12-05 10:21:45 -08:00
amba
ata libata: fix build without BMDMA 2011-11-17 02:11:42 -05:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2011-10-25 13:25:22 +02:00
auxdisplay
base Merge branch 'driver-core-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core 2011-11-21 20:36:26 -08:00
bcma bcma: fix implicit use of export.h contents 2011-10-31 19:32:02 -04:00
block paride: fix potential information leak in pg_read() 2011-11-16 09:21:50 +01:00
bluetooth Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless 2011-11-09 16:22:15 -05:00
cdrom
char fix typo/thinko in get_random_bytes() 2011-11-17 11:42:54 -02:00
clk
clocksource Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
connector
cpufreq [CPUFREQ] db8500: fix build error due to undeclared i variable 2011-11-11 22:28:33 -05:00
cpuidle Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2011-11-07 10:13:52 -08:00
crypto Merge git://github.com/herbertx/crypto 2011-11-25 21:55:07 -08:00
dca drivers/dca: Add export.h for THIS_MODULE to dca-sysfs.c 2011-10-31 19:31:43 -04:00
devfreq PM / devfreq: correct Kconfig dependency 2011-11-14 23:31:35 +01:00
dio
dma Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
edac drivers/edac/mpc85xx_edac.c: fix memory controller compatible for edac 2011-11-24 01:59:38 -06:00
eisa
firewire Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
firmware Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound 2011-12-02 08:10:51 -08:00
gpio gpio: pca953x: Staticise pca953x_get_altdata() 2011-11-21 20:53:15 +01:00
gpu vmwgfx: integer overflow in vmw_kms_update_layout_ioctl() 2011-12-02 10:49:41 +00:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2011-12-02 08:25:46 -08:00
hv
hwmon hwmon: convert drivers/hwmon/* to use module_platform_driver() 2011-11-26 09:48:20 -08:00
hwspinlock Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-08 18:34:16 -08:00
i2c Merge branch 'fixes' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm 2011-12-01 11:53:54 -08:00
ide Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide 2011-11-18 22:04:12 -02:00
idle Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2011-11-07 10:13:52 -08:00
ieee802154
infiniband Merge branches 'cxgb4', 'ipoib', 'misc' and 'qib' into for-next 2011-11-29 18:01:53 -08:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2011-11-22 09:18:06 -08:00
iommu iommu: omap: Fix compile failure 2011-11-08 17:11:57 +01:00
isdn isdn: avoid copying too long drvid 2011-11-29 18:39:37 -05:00
leds Revert "leds: save the delay values after a successful call to blink_set()" 2011-11-15 22:41:50 -02:00
lguest lguest: add export.h to lguest files for THIS_MODULE/EXPORT_SYMBOL 2011-10-31 19:32:13 -04:00
macintosh m68k/irq: Remove obsolete IRQ_FLG_* users 2011-11-08 22:35:48 +01:00
mca
md md/raid5: STRIPE_ACTIVE has lock semantics, add barriers 2011-11-08 16:22:06 +11:00
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2011-11-12 00:03:50 -02:00
memstick drivers/memstick: Add module.h to the prev. implicit modular users 2011-10-31 19:31:52 -04:00
message drivers/message: Add module.h to i2o/pci.c 2011-10-31 19:31:53 -04:00
mfd mfd: fix build failures in recently added ab5500 code 2011-11-07 21:45:14 -05:00
misc Merge branch 'char-misc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc 2011-11-21 20:36:05 -08:00
mmc arm/imx: fix imx6q mmc error when mounting rootfs 2011-11-11 16:53:35 +01:00
mtd MTD: MAPS: bcm963xx-flash.c: explicitly include module.h 2011-11-07 21:26:55 -05:00
net bonding: only use primary address for ARP 2011-11-30 22:59:11 -05:00
nfc drivers/nfc: add module.h to nfcwilink.c 2011-10-31 19:31:54 -04:00
nubus
of of/irq: of_irq_init: add check for parent equal to child node 2011-11-29 08:22:40 -06:00
oprofile
parisc parisc: add module.h to files really requiring it 2011-10-31 19:31:01 -04:00
parport
pci PCI: Rework ASPM disable code 2011-12-05 10:21:45 -08:00
pcmcia Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
pinctrl pinctrl: hide subsystem from the populace 2011-11-10 09:02:12 +01:00
platform platform/x86: fix dell-laptop function prototypes 2011-11-17 10:29:02 -02:00
pnp Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2011-11-07 10:13:52 -08:00
power Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
pps pps gpio client: add missing dependency 2011-11-02 16:07:02 -07:00
ps3 powerpc/ps3: irq: Remove IRQF_DISABLED 2011-11-08 14:51:46 +11:00
ptp
rapidio Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
regulator regulator: twl: fix twl4030 support for smps regulators 2011-11-28 18:58:31 +00:00
rtc rtc: rtc-puv3: Add __devinit and __devexit markers for probe and remove 2011-11-15 17:13:17 +08:00
s390 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2011-11-20 14:59:33 -08:00
sbus
scsi [SCSI] hpsa: Disable ASPM 2011-11-14 10:47:01 -06:00
sfi drivers/sfi: sfi_acpi.c needs sysfs.h 2011-10-31 19:31:57 -04:00
sh Merge branches 'sh/pm-runtime' and 'common/clkfwk' into sh-fixes-for-linus 2011-11-11 16:16:25 +09:00
sn
spi ARM: 7175/1: add subname parameter to mfp_set_groupg callers 2011-11-26 21:58:54 +00:00
ssb ssb: Add export.h to files using EXPORT_SYMBOL/THIS_MODULE 2011-10-31 19:32:08 -04:00
staging Merge branch 'staging-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging 2011-12-02 13:30:25 -08:00
target Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
tc
telephony
thermal thermal: Prevent polling from happening during system suspend 2011-11-06 20:38:49 -05:00
tty Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty 2011-11-21 20:36:46 -08:00
uio uio: Add module.h to implicit drivers/uio users 2011-10-31 19:32:10 -04:00
usb Merge branch 'for-usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci into usb-linus 2011-12-01 11:11:52 -08:00
uwb uwb: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required 2011-10-31 19:32:19 -04:00
vhost
video viafb: correct sync polarity for OLPC DCON 2011-11-22 00:56:17 +00:00
virt
virtio virtio-pci: make reset operation safer 2011-11-24 13:04:48 +10:30
vlynq
w1 Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
watchdog watchdog: fix initialisation printout in s3c2410_wdt 2011-11-16 22:04:17 +01:00
xen xen-gntalloc: signedness bug in add_grefs() 2011-11-16 12:13:48 -05:00
zorro drivers/zorro: Add export.h to proc.c 2011-10-31 19:32:01 -04:00
Kconfig Merge branch 'staging-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging 2011-10-26 15:39:02 +02:00
Makefile Merge branch 'staging-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging 2011-10-26 15:39:02 +02:00