mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-20 00:11:22 +00:00
b375a0495f
29 July 2005, Cambridge, MA: This afternoon Alan Stern submitted a patch to remove the URB_ASYNC_UNLINK flag from the Linux kernel. Mr. Stern explained, "This flag is a relic from an earlier, less-well-designed system. For over a year it hasn't been used for anything other than printing warning messages." An anonymous spokesman for the Linux kernel development community commented, "This is exactly the sort of thing we see happening all the time. As the kernel evolves, support for old techniques and old code can be jettisoned and replaced by newer, better approaches. Proprietary operating systems do not have the freedom or flexibility to change so quickly." Mr. Stern, a staff member at Harvard University's Rowland Institute who works on Linux only as a hobby, noted that the patch (labelled as548) did not update two files, keyspan.c and option.c, in the USB drivers' "serial" subdirectory. "Those files need more extensive changes," he remarked. "They examine the status field of several URBs at times when they're not supposed to. That will need to be fixed before the URB_ASYNC_UNLINK flag is removed." Greg Kroah-Hartman, the kernel maintainer responsible for overseeing all of Linux's USB drivers, did not respond to our inquiries or return our calls. His only comment was "Applied, thanks." Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
||
|---|---|---|
| .. | ||
| atm | ||
| class | ||
| core | ||
| gadget | ||
| host | ||
| image | ||
| input | ||
| media | ||
| misc | ||
| mon | ||
| net | ||
| 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.