linux/drivers/usb/core
Lu Baolu 2d2a316765 usb: core: lpm: set lpm_capable for root hub device
Commit 25cd2882e2 ("usb/xhci: Change how we indicate a host supports
Link PM.") removed the code to set lpm_capable for USB 3.0 super-speed
root hub. The intention of that change was to avoid touching usb core
internal field, a.k.a. lpm_capable, and let usb core to set it by
checking U1 and U2 exit latency values in the descriptor.

Usb core checks and sets lpm_capable in hub_port_init(). Unfortunately,
root hub is a special usb device as it has no parent. Hub_port_init()
will never be called for a root hub device. That means lpm_capable will
by no means be set for the root hub. As the result, lpm isn't functional
at all in Linux kernel.

This patch add the code to check and set lpm_capable when registering a
root hub device. It could be back-ported to kernels as old as v3.15,
that contains the Commit 25cd2882e2 ("usb/xhci: Change how we indicate
a host supports Link PM.").

Cc: stable@vger.kernel.org # 3.15
Reported-by: Kevin Strasser <kevin.strasser@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-22 14:46:50 -07:00
..
buffer.c Usb: core: buffer: fixed the checkpatch warning 2015-05-10 15:44:10 +02:00
config.c usb-core bInterval quirk 2014-08-01 15:47:05 -07:00
devices.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
devio.c USB: devio: fix a condition in async_completed() 2015-05-24 09:29:36 -07:00
driver.c USB: add flag for HCDs that can't receive wakeup requests (isp1760-hcd) 2015-01-31 09:05:06 -08:00
endpoint.c USB: core: be specific about attribute permissions 2013-08-25 15:12:03 -07:00
file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
generic.c staging: usbip: convert usbip-host driver to usb_device_driver 2014-02-07 10:54:30 -08:00
hcd-pci.c USB / PM: Drop CONFIG_PM_RUNTIME from the USB core 2014-12-04 00:51:54 +01:00
hcd.c usb: core: lpm: set lpm_capable for root hub device 2015-07-22 14:46:50 -07:00
hub.c usb: core: lpm: set lpm_capable for root hub device 2015-07-22 14:46:50 -07:00
hub.h usb: hub: convert khubd into workqueue 2014-09-23 22:33:19 -07:00
Kconfig usb: add bus type for USB ULPI 2015-05-13 12:04:55 -05:00
Makefile USB: core: remove CONFIG_USB_DEBUG usage 2013-12-21 16:01:00 -08:00
message.c USB: don't cancel queued resets when unbinding drivers 2015-01-25 20:54:17 +08:00
notify.c
otg_whitelist.h USB: Add OTG PET device to TPL 2015-01-25 21:20:42 +08:00
port.c USB / PM: Drop CONFIG_PM_RUNTIME from the USB core 2014-12-04 00:51:54 +01:00
quirks.c Added another USB product ID for ELAN touchscreen quirks. 2015-05-09 19:23:03 +02:00
sysfs.c USB / PM: Drop CONFIG_PM_RUNTIME from the USB core 2014-12-04 00:51:54 +01:00
urb.c usb: core: allow zero packet flag for interrupt urbs 2014-07-22 16:30:58 -07:00
usb-acpi.c usb: find internal hub tier mismatch via acpi 2014-05-27 16:38:52 -07:00
usb.c USB: Move usb_disabled() towards top of the file 2015-03-26 10:48:22 +01:00
usb.h usb: core: lpm: set lpm_capable for root hub device 2015-07-22 14:46:50 -07:00