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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.
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.