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9b6567e19b
By pass pullup DP in OTG fsm mode when do gadget connect, to let it handled by OTG state machine. This patch can fix the problem you found with my HNP polling patchset after below 3 patches introduced:467a78cusb: chipidea: udc: apply new usb_udc_vbus_handler interface628ef0dusb: udc: add usb_udc_vbus_handlerdfea9c9usb: udc: store usb_udc pointer in struct usb_gadget Problem: - Connect USB cable and MicroAB cable between two boards - Boot up two boards - load g_mass_storage at B-device side, the enumeration will success, and A will see a usb mass-storage device - load g_mass_storage at A-device side, the problem has occurred, the connection will be lost at the beginning, then connect again. This patch is based on commit eff933c1d3a2e046492b3dfc86db813856553a29 (chipidea: pci: make it depends on NOP_USB_XCEIV) on branch peter-usb-dev of git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb.git Signed-off-by: Li Jun <jun.li@freescale.com> Signed-off-by: Peter Chen <peter.chen@freescale.com>
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.