Interface descriptor info (can be multiple per Config):
-I: If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=ssss
-| | | | | | | |__Driver name
-| | | | | | | or "(none)"
-| | | | | | |__InterfaceProtocol
-| | | | | |__InterfaceSubClass
-| | | | |__InterfaceClass
-| | | |__NumberOfEndpoints
-| | |__AlternateSettingNumber
-| |__InterfaceNumber
+I:* If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=ssss
+| | | | | | | | |__Driver name
+| | | | | | | | or "(none)"
+| | | | | | | |__InterfaceProtocol
+| | | | | | |__InterfaceSubClass
+| | | | | |__InterfaceClass
+| | | | |__NumberOfEndpoints
+| | | |__AlternateSettingNumber
+| | |__InterfaceNumber
+| |__ "*" indicates the active altsetting (others are " ")
|__Interface info tag
A given interface may have one or more "alternate" settings.
on how to do this.)
The Interface lines can be used to determine what driver is
-being used for each device.
+being used for each device, and which altsetting it activated.
The Configuration lines could be used to list maximum power
(in milliamps) that a system's USB devices are using.
static const char *format_iface =
/* I: If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=xxxx*/
- "I: If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n";
+ "I:%c If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n";
static const char *format_endpt =
/* E: Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */
{
const struct usb_interface_descriptor *desc = &intfc->altsetting[setno].desc;
const char *driver_name = "";
+ int active = 0;
if (start > end)
return start;
down_read(&usb_bus_type.subsys.rwsem);
- if (iface)
+ if (iface) {
driver_name = (iface->dev.driver
? iface->dev.driver->name
: "(none)");
+ active = (desc == &iface->cur_altsetting->desc);
+ }
start += sprintf(start, format_iface,
+ active ? '*' : ' ', /* mark active altsetting */
desc->bInterfaceNumber,
desc->bAlternateSetting,
desc->bNumEndpoints,