linux/drivers
Sarah Sharp 3b3db02641 xhci: Add infrastructure for host-specific LPM policies.
The choice of U1 and U2 timeouts for USB 3.0 Link Power Management (LPM)
is highly host controller specific.  Here are a few examples of why it's
host specific:

 1. Setting the U1/U2 timeout too short may cause the link to go into
    U1/U2 in between service intervals, which some hosts may tolerate,
    and some may not.

 2. The host controller has to modify its bus schedule in order to take
    into account the Maximum Exit Latency (MEL) to bring all the links
    from the host to the device into U0.  If the MEL is too big, and it
    takes too long to bring the links into an active state, the host
    controller may not be able to service periodic endpoints in time.

 3. Host controllers may also have scheduling limitations that force
    them to disable U1 or U2 if a USB device is behind too many tiers of
    hubs.

We could take an educated guess at what U1/U2 timeouts may work for a
particular host controller.  However, that would result in a binary
search on every new configuration or alt setting installation, with
multiple failed Evaluate Context commands.  Worse, the host may blindly
accept the timeouts and just fail to update its schedule for U1/U2 exit
latencies, which could result in randomly delayed periodic transfers.

Since we don't want to cause jitter in periodic transfers, or delay
config/alt setting changes too much, lay down a framework that xHCI
vendors can extend in order to add their own U1/U2 timeout policies.

To extend the framework, they will need to:

 - Modify the PCI init code to add a new xhci->quirk for their host, and
   set the XHCI_LPM_SUPPORT quirk flag.
 - Add their own vendor-specific hooks, like the ones that will be added
   in xhci_call_host_update_timeout_for_endpoint() and
   xhci_check_tier_policy()
 - Make the LPM enable/disable methods call those functions based on the
   xhci->quirk for their host.

An example will be provided for the Intel xHCI host controller in the
next patch.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
2012-05-18 15:42:03 -07:00
..
accessibility
acpi ACPI: Add _PLD support 2012-05-11 17:03:12 -07:00
amba ARM: 7366/3: amba: Remove AMBA level regulator support 2012-04-13 14:04:08 +01:00
ata Change summary: 2012-05-03 17:16:52 -07:00
atm Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
auxdisplay
base regmap: fix possible memory corruption in regmap_bulk_read() 2012-05-09 15:44:11 +01:00
bcma Merge 3.4-rc6 into usb-next 2012-05-07 09:03:39 -07:00
block connector/userns: replace netlink uses of cap_raised() with capable() 2012-05-10 23:21:39 -04:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth 2012-04-27 15:16:43 -04:00
cdrom
char tty and serial fixes for 3.4-rc2 2012-04-12 15:36:33 -07:00
clk
clocksource Revert "clocksource: Load the ACPI PM clocksource asynchronously" 2012-04-12 00:05:05 +02:00
connector
cpufreq cpufreq: OMAP: fix build errors: depends on ARCH_OMAP2PLUS 2012-04-13 17:57:40 -07:00
cpuidle Merge branches 'idle-fix' and 'misc' into release 2012-04-06 21:48:59 -04:00
crypto crypto: talitos - properly lock access to global talitos registers 2012-04-09 15:13:40 +08:00
dca
devfreq ARM: global cleanups 2012-03-27 16:03:32 -07:00
dio
dma Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-04-26 15:33:36 -07:00
edac Merge branch 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2012-04-06 17:56:20 -07:00
eisa
firewire Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
firmware efivars: Improve variable validation 2012-05-03 17:19:19 -07:00
gpio gpio/exynos: Fix compiler warnings when non-exynos machines are selected 2012-05-11 18:25:53 -06:00
gpu drm/nouveau/i2c: resume use of i2c-algo-bit, rather than custom stack 2012-05-07 11:02:38 +01:00
hid USB: hid-core.c: remove dbg() usage 2012-05-01 21:32:55 -07:00
hsi HSI: hsi_char: Remove max_data_size from sysfs 2012-04-23 14:23:32 +03:00
hv
hwmon hwmon: (coretemp) Increase CPU core limit 2012-05-01 09:16:14 -07:00
hwspinlock
i2c i2c: mxs: disable QUEUE when sending is done 2012-04-27 16:13:29 +02:00
ide Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
idle simple_open: automatically convert to simple_open() 2012-04-05 15:25:50 -07:00
ieee802154
infiniband A few fixes for regressions introduced in 3.4-rc1: 2012-04-26 15:35:35 -07:00
input Merge 3.4-rc6 into usb-next 2012-05-07 09:03:39 -07:00
iommu Merge branch 'akpm' (Andrew's patch-bomb) 2012-04-05 15:30:34 -07:00
isdn tty and serial fixes for 3.4-rc2 2012-04-12 15:36:33 -07:00
leds drivers/leds: correct __devexit annotations 2012-05-10 15:06:44 -07:00
lguest
macintosh Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
mca
md Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-05-12 12:57:01 -07:00
media USB: hdpvr-core.c: remove err() usage 2012-04-25 14:48:49 -07:00
memstick
message Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
mfd mfd: Fix build breakage in omap-usb-host.c 2012-05-01 11:55:04 +02:00
misc Merge branch 'akpm' (Andrew's patch-bomb) 2012-04-05 15:30:34 -07:00
mmc Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-04-26 15:33:36 -07:00
mtd Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-04-26 15:33:36 -07:00
net Merge branch 'v3.5-for-usb' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into usb-next 2012-05-17 09:14:21 -07:00
nfc
nubus Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
of gpio: Fix range check in of_gpio_simple_xlate() 2012-04-10 14:20:56 -06:00
oprofile simple_open: automatically convert to simple_open() 2012-04-05 15:25:50 -07:00
parisc parisc: move definition of PAGE0 to asm/page.h 2012-05-10 15:12:08 -07:00
parport
pci Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-05-05 10:06:06 -07:00
pcmcia Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia 2012-03-29 16:00:48 -07:00
pinctrl pinctrl: implement pinctrl_check_ops 2012-04-11 09:31:02 +02:00
platform Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-05-06 12:19:38 -07:00
pnp Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-03-30 16:45:39 -07:00
power Various small bugfixes and enhancements, plus two new drivers: 2012-03-30 16:09:02 -07:00
pps
ps3
ptp
rapidio
regulator regulator: Actually free the regulator in devm_regulator_put() 2012-05-07 13:14:44 +01:00
remoteproc simple_open: automatically convert to simple_open() 2012-04-05 15:25:50 -07:00
rpmsg
rtc Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-05-04 15:35:09 -07:00
s390 qeth: Use blkt defaults for OSA Express 4 2012-04-24 00:33:17 -04:00
sbus Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
scsi [SCSI] virtio_scsi: fix TMF use-after-free 2012-05-10 08:27:06 +01:00
sfi
sh SuperH updates for 3.4 merge window 2012-03-30 00:09:17 -07:00
sn
spi spi/spi-bfin5xx: Fix flush of last bit after each spi transfer 2012-04-27 12:20:39 -06:00
ssb
staging staging: usb: gadget: Add FunctionFS support to Configurable Composite Gadget driver 2012-05-16 05:32:20 -07:00
target target: Drop incorrect se_lun_acl release for dynamic -> explict ACL conversion 2012-05-11 14:55:19 -07:00
tc
thermal
tty TTY fix for 3.4-rc5 2012-05-02 13:47:49 -07:00
uio
usb xhci: Add infrastructure for host-specific LPM policies. 2012-05-18 15:42:03 -07:00
uwb uwb: fix error handling 2012-04-18 13:15:51 -07:00
vhost vhost-net: fix handle_rx buffer size 2012-05-11 18:16:57 -04:00
video Merge branch 'v3.5-for-usb' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into usb-next 2012-05-17 09:14:21 -07:00
virt
virtio virtio_balloon: fix handling of PAGE_SIZE != 4k 2012-04-15 11:51:06 +03:00
vlynq
w1
watchdog hpwdt: Only BYTE reads/writes to WD Timer port 0x72 2012-04-26 14:38:07 +02:00
xen xen/Kconfig: fix Kconfig layout 2012-05-07 12:26:28 -04:00
zorro
Kconfig Merge branch 'for-next' of git://gitorious.org/kernel-hsi/kernel-hsi 2012-04-02 09:50:40 -07:00
Makefile Merge branch 'for-next' of git://gitorious.org/kernel-hsi/kernel-hsi 2012-04-02 09:50:40 -07:00