mirror of
https://github.com/adulau/aha.git
synced 2025-01-02 14:13:18 +00:00
e9df41c5c5
This patch (as954) implements a suggestion of David Brownell's. Now the host controller drivers are responsible for linking and unlinking URBs to/from their endpoint queues. This eliminates the possiblity of strange situations where usbcore thinks an URB is linked but the HCD thinks it isn't. It also means HCDs no longer have to check for URBs being dequeued before they were fully enqueued. In addition to the core changes, this requires changing every host controller driver and the root-hub URB handler. For the most part the required changes are fairly small; drivers have to call usb_hcd_link_urb_to_ep() in their urb_enqueue method, usb_hcd_check_unlink_urb() in their urb_dequeue method, and usb_hcd_unlink_urb_from_ep() before giving URBs back. A few HCDs make matters more complicated by the way they split up the flow of control. In addition some method interfaces get changed. The endpoint argument for urb_enqueue is now redundant so it is removed. The unlink status is required by usb_hcd_check_unlink_urb(), so it has been added to urb_dequeue. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: David Brownell <david-b@pacbell.net> CC: Olav Kongas <ok@artecdesign.ee> CC: Tony Olech <tony.olech@elandigitalsystems.com> CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
||
|---|---|---|
| .. | ||
| atm | ||
| class | ||
| core | ||
| gadget | ||
| host | ||
| image | ||
| misc | ||
| mon | ||
| serial | ||
| storage | ||
| Kconfig | ||
| Makefile | ||
| README | ||
| usb-skeleton.c | ||
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 ("khubd").
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.