mirror of https://gitee.com/openkylin/linux.git
379cacc5e5
When a USB device attached to a root-hub port sends a wakeup request to a sleeping system, we do not report the wakeup event to the PM core. This is because a system resume involves waking up all suspended USB ports as quickly as possible; without the normal USB_RESUME_TIMEOUT delay, the host controller driver doesn't set the USB_PORT_STAT_C_SUSPEND flag and so usb_port_resume() doesn't realize that a wakeup request was received. However, some environments (such as Chrome OS) want to have all wakeup events reported so they can be ascribed to the appropriate device. To accommodate these environments, this patch adds a new routine to the hub driver and a corresponding new HCD method to be used when a root hub resumes. The HCD method returns a bitmap of ports that have initiated a wakeup signal but not yet completed resuming. The hub driver can then report to the PM core that the child devices attached to these ports initiated a wakeup event. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Suggested-by: Anshuman Gupta <anshuman.gupta@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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| chipidea | ||
| class | ||
| common | ||
| core | ||
| dwc2 | ||
| dwc3 | ||
| early | ||
| gadget | ||
| host | ||
| image | ||
| isp1760 | ||
| misc | ||
| mon | ||
| mtu3 | ||
| musb | ||
| phy | ||
| renesas_usbhs | ||
| roles | ||
| serial | ||
| storage | ||
| typec | ||
| usbip | ||
| wusbcore | ||
| Kconfig | ||
| Makefile | ||
| README | ||
| usb-skeleton.c | ||
README
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("hub_wq").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
../input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
../media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
../net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.