summaryrefslogtreecommitdiffstats
path: root/Documentation/usb
diff options
context:
space:
mode:
authorDmitry Torokhov <dmitry.torokhov@gmail.com>2012-04-21 23:28:35 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2012-04-21 23:28:35 -0700
commit57b8628bb0ac4e47c806e45c5bbd89282e93869b (patch)
treeee9289f0898054474b7e5054abdb3ffb78666436 /Documentation/usb
parent486c8aba39e5f194519cd5c0e85e5d1de8b74b03 (diff)
parent66f75a5d028beaf67c931435fdc3e7823125730c (diff)
downloadblackbird-op-linux-57b8628bb0ac4e47c806e45c5bbd89282e93869b.tar.gz
blackbird-op-linux-57b8628bb0ac4e47c806e45c5bbd89282e93869b.zip
Merge commit 'v3.4-rc4' into next
Diffstat (limited to 'Documentation/usb')
-rw-r--r--Documentation/usb/URB.txt22
-rw-r--r--Documentation/usb/mtouchusb.txt2
-rw-r--r--Documentation/usb/power-management.txt5
-rw-r--r--Documentation/usb/proc_usb_info.txt2
-rw-r--r--Documentation/usb/usbmon.txt6
5 files changed, 30 insertions, 7 deletions
diff --git a/Documentation/usb/URB.txt b/Documentation/usb/URB.txt
index 8ffce746d496..00d2c644068e 100644
--- a/Documentation/usb/URB.txt
+++ b/Documentation/usb/URB.txt
@@ -168,6 +168,28 @@ that if the completion handler or anyone else tries to resubmit it
they will get a -EPERM error. Thus you can be sure that when
usb_kill_urb() returns, the URB is totally idle.
+There is a lifetime issue to consider. An URB may complete at any
+time, and the completion handler may free the URB. If this happens
+while usb_unlink_urb or usb_kill_urb is running, it will cause a
+memory-access violation. The driver is responsible for avoiding this,
+which often means some sort of lock will be needed to prevent the URB
+from being deallocated while it is still in use.
+
+On the other hand, since usb_unlink_urb may end up calling the
+completion handler, the handler must not take any lock that is held
+when usb_unlink_urb is invoked. The general solution to this problem
+is to increment the URB's reference count while holding the lock, then
+drop the lock and call usb_unlink_urb or usb_kill_urb, and then
+decrement the URB's reference count. You increment the reference
+count by calling
+
+ struct urb *usb_get_urb(struct urb *urb)
+
+(ignore the return value; it is the same as the argument) and
+decrement the reference count by calling usb_free_urb. Of course,
+none of this is necessary if there's no danger of the URB being freed
+by the completion handler.
+
1.7. What about the completion handler?
diff --git a/Documentation/usb/mtouchusb.txt b/Documentation/usb/mtouchusb.txt
index 86302cd53ed3..a91adb26ea7b 100644
--- a/Documentation/usb/mtouchusb.txt
+++ b/Documentation/usb/mtouchusb.txt
@@ -1,7 +1,7 @@
CHANGES
- 0.3 - Created based off of scanner & INSTALL from the original touchscreen
- driver on freshmeat (http://freshmeat.net/projects/3mtouchscreendriver)
+ driver on freecode (http://freecode.com/projects/3mtouchscreendriver)
- Amended for linux-2.4.18, then 2.4.19
- 0.5 - Complete rewrite using Linux Input in 2.6.3
diff --git a/Documentation/usb/power-management.txt b/Documentation/usb/power-management.txt
index 12511c98cc4f..4204eb01fd38 100644
--- a/Documentation/usb/power-management.txt
+++ b/Documentation/usb/power-management.txt
@@ -179,7 +179,8 @@ do:
modprobe usbcore autosuspend=5
-Equivalently, you could add to /etc/modprobe.conf a line saying:
+Equivalently, you could add to a configuration file in /etc/modprobe.d
+a line saying:
options usbcore autosuspend=5
@@ -345,7 +346,7 @@ autosuspend the device.
Drivers need not be concerned about balancing changes to the usage
counter; the USB core will undo any remaining "get"s when a driver
is unbound from its interface. As a corollary, drivers must not call
-any of the usb_autopm_* functions after their diconnect() routine has
+any of the usb_autopm_* functions after their disconnect() routine has
returned.
Drivers using the async routines are responsible for their own
diff --git a/Documentation/usb/proc_usb_info.txt b/Documentation/usb/proc_usb_info.txt
index afe596d5f201..c9c3f0f5ad7b 100644
--- a/Documentation/usb/proc_usb_info.txt
+++ b/Documentation/usb/proc_usb_info.txt
@@ -7,7 +7,7 @@ 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 filsystem isn't used at all. Instead
+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.
diff --git a/Documentation/usb/usbmon.txt b/Documentation/usb/usbmon.txt
index 5335fa8b06eb..c42bb9cd3b43 100644
--- a/Documentation/usb/usbmon.txt
+++ b/Documentation/usb/usbmon.txt
@@ -183,10 +183,10 @@ An input control transfer to get a port status.
d5ea89a0 3575914555 S Ci:1:001:0 s a3 00 0000 0003 0004 4 <
d5ea89a0 3575914560 C Ci:1:001:0 0 4 = 01050000
-An output bulk transfer to send a SCSI command 0x5E in a 31-byte Bulk wrapper
-to a storage device at address 5:
+An output bulk transfer to send a SCSI command 0x28 (READ_10) in a 31-byte
+Bulk wrapper to a storage device at address 5:
-dd65f0e8 4128379752 S Bo:1:005:2 -115 31 = 55534243 5e000000 00000000 00000600 00000000 00000000 00000000 000000
+dd65f0e8 4128379752 S Bo:1:005:2 -115 31 = 55534243 ad000000 00800000 80010a28 20000000 20000040 00000000 000000
dd65f0e8 4128379808 C Bo:1:005:2 0 31 >
* Raw binary format and API
OpenPOWER on IntegriCloud