1# SPDX-License-Identifier: GPL-2.0 2# 3# USB Core configuration 4# 5config USB_ANNOUNCE_NEW_DEVICES 6 bool "USB announce new devices" 7 help 8 Say Y here if you want the USB core to always announce the 9 idVendor, idProduct, Manufacturer, Product, and SerialNumber 10 strings for every new USB device to the syslog. This option is 11 usually used by distro vendors to help with debugging and to 12 let users know what specific device was added to the machine 13 in what location. 14 15 If you do not want this kind of information sent to the system 16 log, or have any doubts about this, say N here. 17 18comment "Miscellaneous USB options" 19 20config USB_DEFAULT_PERSIST 21 bool "Enable USB persist by default" 22 default y 23 help 24 Say N here if you don't want USB power session persistence 25 enabled by default. If you say N it will make suspended USB 26 devices that lose power get reenumerated as if they had been 27 unplugged, causing any mounted filesystems to be lost. The 28 persist feature can still be enabled for individual devices 29 through the power/persist sysfs node. See 30 Documentation/driver-api/usb/persist.rst for more info. 31 32 If you have any questions about this, say Y here, only say N 33 if you know exactly what you are doing. 34 35config USB_FEW_INIT_RETRIES 36 bool "Limit USB device initialization to only a few retries" 37 help 38 When a new USB device is detected, the kernel tries very hard 39 to initialize and enumerate it, with lots of nested retry loops. 40 This almost always works, but when it fails it can take a long time. 41 This option tells the kernel to make only a few retry attempts, 42 so that the total time required for a failed initialization is 43 no more than 30 seconds (as required by the USB OTG spec). 44 45 Say N here unless you require new-device enumeration failure to 46 occur within 30 seconds (as might be needed in an embedded 47 application). 48 49config USB_DYNAMIC_MINORS 50 bool "Dynamic USB minor allocation" 51 help 52 If you say Y here, the USB subsystem will use dynamic minor 53 allocation for any device that uses the USB major number. 54 This means that you can have more than 16 of a single type 55 of device (like USB printers). 56 57 If you are unsure about this, say N here. 58 59config USB_OTG 60 bool "OTG support" 61 depends on PM 62 help 63 The most notable feature of USB OTG is support for a 64 "Dual-Role" device, which can act as either a device 65 or a host. The initial role is decided by the type of 66 plug inserted and can be changed later when two dual 67 role devices talk to each other. 68 69 Select this only if your board has Mini-AB/Micro-AB 70 connector. 71 72config USB_OTG_PRODUCTLIST 73 bool "Rely on OTG and EH Targeted Peripherals List" 74 depends on USB 75 help 76 If you say Y here, the "otg_productlist.h" file will be used as a 77 product list, so USB peripherals not listed there will be 78 rejected during enumeration. This behavior is required by the 79 USB OTG and EH specification for all devices not on your product's 80 "Targeted Peripherals List". "Embedded Hosts" are likewise 81 allowed to support only a limited number of peripherals. 82 83config USB_OTG_DISABLE_EXTERNAL_HUB 84 bool "Disable external hubs" 85 depends on USB_OTG || EXPERT 86 help 87 If you say Y here, then Linux will refuse to enumerate 88 external hubs. OTG hosts are allowed to reduce hardware 89 and software costs by not supporting external hubs. So 90 are "Embedded Hosts" that don't offer OTG support. 91 92config USB_OTG_FSM 93 tristate "USB 2.0 OTG FSM implementation" 94 depends on USB && USB_OTG 95 select USB_PHY 96 help 97 Implements OTG Finite State Machine as specified in On-The-Go 98 and Embedded Host Supplement to the USB Revision 2.0 Specification. 99 100config USB_LEDS_TRIGGER_USBPORT 101 tristate "USB port LED trigger" 102 depends on USB && LEDS_TRIGGERS 103 help 104 This driver allows LEDs to be controlled by USB events. Enabling this 105 trigger allows specifying list of USB ports that should turn on LED 106 when some USB device gets connected. 107 108config USB_AUTOSUSPEND_DELAY 109 int "Default autosuspend delay" 110 depends on USB 111 default 2 112 help 113 The default autosuspend delay in seconds. Can be overridden 114 with the usbcore.autosuspend command line or module parameter. 115 116 The default value Linux has always had is 2 seconds. Change 117 this value if you want a different delay and cannot modify 118 the command line or module parameter. 119