diff options
Diffstat (limited to 'Documentation/usb/proc_usb_info.txt')
| -rw-r--r-- | Documentation/usb/proc_usb_info.txt | 43 |
1 files changed, 28 insertions, 15 deletions
diff --git a/Documentation/usb/proc_usb_info.txt b/Documentation/usb/proc_usb_info.txt index fafcd472326..98be9198267 100644 --- a/Documentation/usb/proc_usb_info.txt +++ b/Documentation/usb/proc_usb_info.txt @@ -1,12 +1,17 @@ /proc/bus/usb filesystem output =============================== -(version 2003.05.30) +(version 2010.09.13) The usbfs filesystem for USB devices is traditionally mounted at /proc/bus/usb. It provides the /proc/bus/usb/devices file, as well as the /proc/bus/usb/BBB/DDD files. +In many modern systems the usbfs filesystem isn't used at all. Instead +USB device nodes are created under /dev/usb/ or someplace similar. The +"devices" file is available in debugfs, typically as +/sys/kernel/debug/usb/devices. + **NOTE**: If /proc/bus/usb appears empty, and a host controller driver has been linked, then you need to mount the @@ -49,9 +54,12 @@ it and 002/048 sometime later. These files can be read as binary data. The binary data consists of first the device descriptor, then the descriptors for each -configuration of the device. Multi-byte fields in the device and -configuration descriptors, but not other descriptors, are converted -to host endianness by the kernel. This information is also shown +configuration of the device. Multi-byte fields in the device descriptor +are converted to host endianness by the kernel. The configuration +descriptors are in bus endian format! The configuration descriptor +are wTotalLength bytes apart. If a device returns less configuration +descriptor data than indicated by wTotalLength there will be a hole in +the file for the missing bytes. This information is also shown in text form by the /proc/bus/usb/devices file, described later. These files may also be used to write user-level drivers for the USB @@ -106,8 +114,8 @@ Legend: Topology info: -T: Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=ddd MxCh=dd -| | | | | | | | |__MaxChildren +T: Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=dddd MxCh=dd +| | | | | | | | |__MaxChildren | | | | | | | |__Device Speed in Mbps | | | | | | |__DeviceNumber | | | | | |__Count of devices at this level @@ -120,8 +128,13 @@ T: Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=ddd MxCh=dd Speed may be: 1.5 Mbit/s for low speed USB 12 Mbit/s for full speed USB - 480 Mbit/s for high speed USB (added for USB 2.0) + 480 Mbit/s for high speed USB (added for USB 2.0); + also used for Wireless USB, which has no fixed speed + 5000 Mbit/s for SuperSpeed USB (added for USB 3.0) + For reasons lost in the mists of time, the Port number is always + too low by 1. For example, a device plugged into port 4 will + show up with "Port=03". Bandwidth info: B: Alloc=ddd/ddd us (xx%), #Int=ddd, #Iso=ddd @@ -291,7 +304,7 @@ Here's an example, from a system which has a UHCI root hub, an external hub connected to the root hub, and a mouse and a serial converter connected to the external hub. -T: Bus=00 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 2 +T: Bus=00 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 2 B: Alloc= 28/900 us ( 3%), #Int= 2, #Iso= 0 D: Ver= 1.00 Cls=09(hub ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1 P: Vendor=0000 ProdID=0000 Rev= 0.00 @@ -301,21 +314,21 @@ C:* #Ifs= 1 Cfg#= 1 Atr=40 MxPwr= 0mA I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub E: Ad=81(I) Atr=03(Int.) MxPS= 8 Ivl=255ms -T: Bus=00 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 4 +T: Bus=00 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 4 D: Ver= 1.00 Cls=09(hub ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1 P: Vendor=0451 ProdID=1446 Rev= 1.00 C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=100mA I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub E: Ad=81(I) Atr=03(Int.) MxPS= 1 Ivl=255ms -T: Bus=00 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#= 3 Spd=1.5 MxCh= 0 +T: Bus=00 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#= 3 Spd=1.5 MxCh= 0 D: Ver= 1.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1 P: Vendor=04b4 ProdID=0001 Rev= 0.00 C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=100mA I: If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=02 Driver=mouse E: Ad=81(I) Atr=03(Int.) MxPS= 3 Ivl= 10ms -T: Bus=00 Lev=02 Prnt=02 Port=02 Cnt=02 Dev#= 4 Spd=12 MxCh= 0 +T: Bus=00 Lev=02 Prnt=02 Port=02 Cnt=02 Dev#= 4 Spd=12 MxCh= 0 D: Ver= 1.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1 P: Vendor=0565 ProdID=0001 Rev= 1.08 S: Manufacturer=Peracom Networks, Inc. @@ -330,12 +343,12 @@ E: Ad=82(I) Atr=03(Int.) MxPS= 8 Ivl= 8ms Selecting only the "T:" and "I:" lines from this (for example, by using "procusb ti"), we have: -T: Bus=00 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 2 -T: Bus=00 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 4 +T: Bus=00 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 2 +T: Bus=00 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 4 I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub -T: Bus=00 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#= 3 Spd=1.5 MxCh= 0 +T: Bus=00 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#= 3 Spd=1.5 MxCh= 0 I: If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=02 Driver=mouse -T: Bus=00 Lev=02 Prnt=02 Port=02 Cnt=02 Dev#= 4 Spd=12 MxCh= 0 +T: Bus=00 Lev=02 Prnt=02 Port=02 Cnt=02 Dev#= 4 Spd=12 MxCh= 0 I: If#= 0 Alt= 0 #EPs= 3 Cls=00(>ifc ) Sub=00 Prot=00 Driver=serial |