path: root/Documentation
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authorLinus Torvalds <torvalds@linux-foundation.org>2012-04-12 15:37:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-04-12 15:37:21 -0700
commit7c427f45503f77f148cc2b66864e0684c60fa3a0 (patch)
tree5cd354211d9b926bc16dcf0a02e21911e6d46039 /Documentation
parentf4f9c1ac78c5c20150f03c370c2bd7eca44f5127 (diff)
parent9de29225bdd25958c1fa82521ff02726f1cab953 (diff)
Merge tag 'usb-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH: "Here are a number of fixes for the USB core and drivers for 3.4-rc2 Lots of tiny xhci fixes here, a few usb-serial driver fixes and new device ids, and a smattering of other minor fixes in different USB drivers. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'usb-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (30 commits) USB: update usbtmc api documentation xHCI: Correct the #define XHCI_LEGACY_DISABLE_SMI xHCI: use gfp flags from caller instead of GFP_ATOMIC xHCI: add XHCI_RESET_ON_RESUME quirk for VIA xHCI host USB: fix bug of device descriptor got from superspeed device xhci: Fix register save/restore order. xhci: Restore event ring dequeue pointer on resume. xhci: Don't write zeroed pointers to xHC registers. xhci: Warn when hosts don't halt. xhci: don't re-enable IE constantly usb: xhci: fix section mismatch in linux-next xHCI: correct to print the true HSEE of USBCMD USB: serial: fix race between probe and open UHCI: hub_status_data should indicate if ports are resuming EHCI: keep track of ports being resumed and indicate in hub_status_data USB: fix race between root-hub suspend and remote wakeup USB: sierra: add support for Sierra Wireless MC7710 USB: ftdi_sio: fix race condition in TIOCMIWAIT, and abort of TIOCMIWAIT when the device is removed USB: ftdi_sio: fix status line change handling for TIOCMIWAIT and TIOCGICOUNT USB: don't ignore suspend errors for root hubs ...
Diffstat (limited to 'Documentation')
3 files changed, 32 insertions, 10 deletions
diff --git a/Documentation/ABI/stable/sysfs-driver-usb-usbtmc b/Documentation/ABI/stable/sysfs-driver-usb-usbtmc
index 2a7f9a00cb0a..e960cd027e1e 100644
--- a/Documentation/ABI/stable/sysfs-driver-usb-usbtmc
+++ b/Documentation/ABI/stable/sysfs-driver-usb-usbtmc
@@ -1,5 +1,5 @@
-What: /sys/bus/usb/drivers/usbtmc/devices/*/interface_capabilities
-What: /sys/bus/usb/drivers/usbtmc/devices/*/device_capabilities
+What: /sys/bus/usb/drivers/usbtmc/*/interface_capabilities
+What: /sys/bus/usb/drivers/usbtmc/*/device_capabilities
Date: August 2008
Contact: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
@@ -12,8 +12,8 @@ Description:
The files are read only.
-What: /sys/bus/usb/drivers/usbtmc/devices/*/usb488_interface_capabilities
-What: /sys/bus/usb/drivers/usbtmc/devices/*/usb488_device_capabilities
+What: /sys/bus/usb/drivers/usbtmc/*/usb488_interface_capabilities
+What: /sys/bus/usb/drivers/usbtmc/*/usb488_device_capabilities
Date: August 2008
Contact: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
@@ -27,7 +27,7 @@ Description:
The files are read only.
-What: /sys/bus/usb/drivers/usbtmc/devices/*/TermChar
+What: /sys/bus/usb/drivers/usbtmc/*/TermChar
Date: August 2008
Contact: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
@@ -40,7 +40,7 @@ Description:
sent to the device or not.
-What: /sys/bus/usb/drivers/usbtmc/devices/*/TermCharEnabled
+What: /sys/bus/usb/drivers/usbtmc/*/TermCharEnabled
Date: August 2008
Contact: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
@@ -51,7 +51,7 @@ Description:
published by the USB-IF.
-What: /sys/bus/usb/drivers/usbtmc/devices/*/auto_abort
+What: /sys/bus/usb/drivers/usbtmc/*/auto_abort
Date: August 2008
Contact: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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/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