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8c03356a55
This patch (as738b) fixes numerous problems in the controller/root-hub suspend/resume/remote-wakeup support in ehci-hcd: The bus_resume() routine should wake up only the ports that were suspended by bus_suspend(). Ports that were already suspended should remain that way. The interrupt mask is used to detect loss of power in the bus_resume() routine (if the mask is 0 then power was lost). However bus_suspend() always sets the mask to 0. Instead the mask should retain its normal value, with port-change-detect interrupts disabled if remote wakeup is turned off. The interrupt mask should be reset to its correct value at the end of bus_resume() regardless of whether power was lost. bus_resume() reinitializes the operational registers if power was lost. However those registers are not in the aux power well, hence they can lose their values whenever the controller is put into D3. They should always be reinitialized. When a port-change interrupt occurs and the root hub is suspended, the interrupt handler should request a root-hub resume instead of starting up the controller all by itself. There's no need for the interrupt handler to request a root-hub resume every time a suspended port sends a remote-wakeup request. The pci_resume() method doesn't need to check for connected ports when deciding whether or not to reset the controller. It can make that decision based on whether Vaux power was maintained. Even when the controller does not need to be reset, pci_resume() must undo the effect of pci_suspend() by re-enabling the interrupt mask. If power was lost, pci_resume() must not call ehci_run(). At this point the root hub is still supposed to be suspended, not running. It's enough to rewrite the command register and set the configured_flag. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
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| atm | ||
| class | ||
| core | ||
| gadget | ||
| host | ||
| image | ||
| input | ||
| 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.