0001 # SPDX-License-Identifier: GPL-2.0
0002 #
0003 # USB Core configuration
0004 #
0005 config USB_ANNOUNCE_NEW_DEVICES
0006 bool "USB announce new devices"
0007 help
0008 Say Y here if you want the USB core to always announce the
0009 idVendor, idProduct, Manufacturer, Product, and SerialNumber
0010 strings for every new USB device to the syslog. This option is
0011 usually used by distro vendors to help with debugging and to
0012 let users know what specific device was added to the machine
0013 in what location.
0014
0015 If you do not want this kind of information sent to the system
0016 log, or have any doubts about this, say N here.
0017
0018 comment "Miscellaneous USB options"
0019
0020 config USB_DEFAULT_PERSIST
0021 bool "Enable USB persist by default"
0022 default y
0023 help
0024 Say N here if you don't want USB power session persistence
0025 enabled by default. If you say N it will make suspended USB
0026 devices that lose power get reenumerated as if they had been
0027 unplugged, causing any mounted filesystems to be lost. The
0028 persist feature can still be enabled for individual devices
0029 through the power/persist sysfs node. See
0030 Documentation/driver-api/usb/persist.rst for more info.
0031
0032 If you have any questions about this, say Y here, only say N
0033 if you know exactly what you are doing.
0034
0035 config USB_FEW_INIT_RETRIES
0036 bool "Limit USB device initialization to only a few retries"
0037 help
0038 When a new USB device is detected, the kernel tries very hard
0039 to initialize and enumerate it, with lots of nested retry loops.
0040 This almost always works, but when it fails it can take a long time.
0041 This option tells the kernel to make only a few retry attempts,
0042 so that the total time required for a failed initialization is
0043 no more than 30 seconds (as required by the USB OTG spec).
0044
0045 Say N here unless you require new-device enumeration failure to
0046 occur within 30 seconds (as might be needed in an embedded
0047 application).
0048
0049 config USB_DYNAMIC_MINORS
0050 bool "Dynamic USB minor allocation"
0051 help
0052 If you say Y here, the USB subsystem will use dynamic minor
0053 allocation for any device that uses the USB major number.
0054 This means that you can have more than 16 of a single type
0055 of device (like USB printers).
0056
0057 If you are unsure about this, say N here.
0058
0059 config USB_OTG
0060 bool "OTG support"
0061 depends on PM
0062 help
0063 The most notable feature of USB OTG is support for a
0064 "Dual-Role" device, which can act as either a device
0065 or a host. The initial role is decided by the type of
0066 plug inserted and can be changed later when two dual
0067 role devices talk to each other.
0068
0069 Select this only if your board has Mini-AB/Micro-AB
0070 connector.
0071
0072 config USB_OTG_PRODUCTLIST
0073 bool "Rely on OTG and EH Targeted Peripherals List"
0074 depends on USB
0075 help
0076 If you say Y here, the "otg_productlist.h" file will be used as a
0077 product list, so USB peripherals not listed there will be
0078 rejected during enumeration. This behavior is required by the
0079 USB OTG and EH specification for all devices not on your product's
0080 "Targeted Peripherals List". "Embedded Hosts" are likewise
0081 allowed to support only a limited number of peripherals.
0082
0083 config USB_OTG_DISABLE_EXTERNAL_HUB
0084 bool "Disable external hubs"
0085 depends on USB_OTG || EXPERT
0086 help
0087 If you say Y here, then Linux will refuse to enumerate
0088 external hubs. OTG hosts are allowed to reduce hardware
0089 and software costs by not supporting external hubs. So
0090 are "Embedded Hosts" that don't offer OTG support.
0091
0092 config USB_OTG_FSM
0093 tristate "USB 2.0 OTG FSM implementation"
0094 depends on USB && USB_OTG
0095 select USB_PHY
0096 help
0097 Implements OTG Finite State Machine as specified in On-The-Go
0098 and Embedded Host Supplement to the USB Revision 2.0 Specification.
0099
0100 config USB_LEDS_TRIGGER_USBPORT
0101 tristate "USB port LED trigger"
0102 depends on USB && LEDS_TRIGGERS
0103 help
0104 This driver allows LEDs to be controlled by USB events. Enabling this
0105 trigger allows specifying list of USB ports that should turn on LED
0106 when some USB device gets connected.
0107
0108 config USB_AUTOSUSPEND_DELAY
0109 int "Default autosuspend delay"
0110 depends on USB
0111 default 2
0112 help
0113 The default autosuspend delay in seconds. Can be overridden
0114 with the usbcore.autosuspend command line or module parameter.
0115
0116 The default value Linux has always had is 2 seconds. Change
0117 this value if you want a different delay and cannot modify
0118 the command line or module parameter.
