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An empty port can transition to either Inactive or Compliance Mode if a
newly connected USB 3.0 device fails to link train. In that case, we
issue a warm reset. Some devices, such as John's Roseweil eusb3
enclosure, slip back into Compliance Mode after the warm reset.
The current warm reset code does not check for device connect status on
warm reset completion, and it incorrectly reports the warm reset
succeeded. This causes the USB core to attempt to send a Set Address
control transfer to a port in Compliance Mode, which will always fail.
Make hub_port_wait_reset check the current connect status and link state
after the warm reset completes. Return a failure status if the device
is disconnected or the link state is Compliance Mode or SS.Inactive.
Make hub_events disable the port if warm reset fails. This will disable
the port, and then bring it back into the RxDetect state. Make the USB
core ignore the connect change until the device reconnects.
Note that this patch does NOT handle connected devices slipping into the
Inactive state very well. This is a concern, because devices can go
into the Inactive state on U1/U2 exit failure. However, the fix for
that case is too large for stable, so it will be submitted in a separate
patch.
This patch should be backported to kernels as old as 3.2, contain the
commit ID
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| atm | ||
| c67x00 | ||
| chipidea | ||
| class | ||
| core | ||
| dwc3 | ||
| early | ||
| gadget | ||
| host | ||
| image | ||
| misc | ||
| mon | ||
| musb | ||
| otg | ||
| phy | ||
| renesas_usbhs | ||
| serial | ||
| storage | ||
| wusbcore | ||
| Kconfig | ||
| Makefile | ||
| README | ||
| usb-common.c | ||
| 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.