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https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
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3f0479e00a
Make the USB core check the bandwidth when switching from one interface alternate setting to another. Also check the bandwidth when resetting a configuration (so that alt setting 0 is used). If this check fails, the device's state is unchanged. If the device refuses the new alt setting, re-instate the old alt setting in the host controller hardware. If a USB device doesn't have an alternate interface setting 0, install the first alt setting in its descriptors when a new configuration is requested, or the device is reset. Add a mutex per root hub to protect bandwidth operations: adding/reseting/changing configurations, and changing alternate interface settings. We want to ensure that the xHCI host controller and the USB device are set up for the same configurations and alternate settings. There are two (possibly three) steps to do this: 1. The host controller needs to check that bandwidth is available for a different setting, by issuing and waiting for a configure endpoint command. 2. Once that returns successfully, a control message is sent to the device. 3. If that fails, the host controller must be notified through another configure endpoint command. The mutex is used to make these three operations seem atomic, to prevent another driver from using more bandwidth for a different device while we're in the middle of these operations. While we're touching the bandwidth code, rename usb_hcd_check_bandwidth() to usb_hcd_alloc_bandwidth(). This function does more than just check that the bandwidth change won't exceed the bus bandwidth; it actually changes the bandwidth configuration in the xHCI host controller. 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 | ||
early | ||
gadget | ||
host | ||
image | ||
misc | ||
mon | ||
musb | ||
otg | ||
serial | ||
storage | ||
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 ("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.