839c817ce6
For upcoming patches, we need to keep information about the bandwidth domains under the xHCI host. Each root port is a separate primary bandwidth domain, and each high speed hub's TT (and potentially each port on a multi-TT hub) is a secondary bandwidth domain. If the table were in text form, it would look a bit like this: EP Interval Sum of Number Largest Max Max Packet of Packets Packet Size Overhead 0 N mps overhead ... 15 N mps overhead Overhead is the maximum packet overhead (for bit stuffing, CRC, protocol overhead, etc) for all the endpoints in this interval. Devices with different speeds have different max packet overhead. For example, if there is a low speed and a full speed endpoint that both have an interval of 3, we would use the higher overhead (the low speed overhead). Interval 0 is a bit special, since we really just want to know the sum of the max ESIT payloads instead of the largest max packet size. That's stored in the interval0_esit_payload variable. For root ports, we also need to keep track of the number of active TTs. For each root port, and each TT under a root port, store some information about the bandwidth consumption. Dynamically allocate an array of root port bandwidth information for the number of root ports on the xHCI host. Each root port stores a list of TTs under the root port. A single TT hub only has one entry in the list, but a multi-TT hub will have an entry per port. When the USB core says that a USB device is a hub, create one or more entries in the root port TT list for the hub. When a device is deleted, and it is a hub, search through the root port TT list and delete all TT entries for the hub. Keep track of which TT entry is associated with a device under a TT. LS/FS devices attached directly to the root port will have usb_device->tt set to the roothub. Ignore that, and treat it like a primary bandwidth domain, since there isn't really a high speed bus between the roothub and the host. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
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| atm | ||
| c67x00 | ||
| class | ||
| core | ||
| dwc3 | ||
| early | ||
| gadget | ||
| host | ||
| image | ||
| misc | ||
| mon | ||
| musb | ||
| otg | ||
| renesas_usbhs | ||
| serial | ||
| storage | ||
| 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 ("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.