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aa7381876c
In chipidea IP RTL, there is a very limited design for siTD, the detail like below: There is no Max Packet Size at siTD, so it uses one constant for both Max Packet Size for packet and the packet size for the last transaction when considering schedule. If the ttctrl.ttha does not match against Hub Address field in siTD, this constant is 188 bytes, else this constant is 1023 bytes. If the ttctrl.ttha is non-zero value, RTL will use 188 as this constant, so it will lose the data if the packet size is larger than 188 bytes, eg, if we playback a wav which format is 48khz, 16 bits, 2 channels, the packet size will be 192bytes, but the controller will only send 188 bytes for this packet, the noise will be heared using USB audio card. The use case is single transaction, but higher frame rate. If the ttctr.ttha is zero value, we can send 1023 bytes within one transaction, but the controller will not accept the coming tranaction if it considers the schedule time is less than 1023 bytes. So the limitation is we can't schedule as many as transactions within frame. If the total bytes is already 256 bytes for previous transactions within frame, it can't accept another transaction. The use case is multiple transactions, but less frame rate. Signed-off-by: Peter Chen <peter.chen@nxp.com> |
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| atm | ||
| c67x00 | ||
| chipidea | ||
| class | ||
| common | ||
| core | ||
| dwc2 | ||
| dwc3 | ||
| early | ||
| gadget | ||
| host | ||
| image | ||
| isp1760 | ||
| misc | ||
| mon | ||
| musb | ||
| phy | ||
| renesas_usbhs | ||
| serial | ||
| storage | ||
| usbip | ||
| wusbcore | ||
| 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 ("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.