Merge commit 'v3.0-rc7' into devicetree/next

13 files changed, 131 insertions, 137 deletions

diff --git a/Documentation/Changes b/Documentation/Changes
index 5f4828a0..b175808 100644
--- a/Documentation/Changes
+++ b/Documentation/Changes
@@ -2,13 +2,7 @@ Intro
 =====
 
 This document is designed to provide a list of the minimum levels of
-software necessary to run the 2.6 kernels, as well as provide brief
-instructions regarding any other "Gotchas" users may encounter when
-trying life on the Bleeding Edge.  If upgrading from a pre-2.4.x
-kernel, please consult the Changes file included with 2.4.x kernels for
-additional information; most of that information will not be repeated
-here.  Basically, this document assumes that your system is already
-functional and running at least 2.4.x kernels.
+software necessary to run the 3.0 kernels.
 
 This document is originally based on my "Changes" file for 2.0.x kernels
 and therefore owes credit to the same people as that file (Jared Mauch,
@@ -22,11 +16,10 @@ Upgrade to at *least* these software revisions before thinking you've
 encountered a bug!  If you're unsure what version you're currently
 running, the suggested command should tell you.
 
-Again, keep in mind that this list assumes you are already
-functionally running a Linux 2.4 kernel.  Also, not all tools are
-necessary on all systems; obviously, if you don't have any ISDN
-hardware, for example, you probably needn't concern yourself with
-isdn4k-utils.
+Again, keep in mind that this list assumes you are already functionally
+running a Linux kernel.  Also, not all tools are necessary on all
+systems; obviously, if you don't have any ISDN hardware, for example,
+you probably needn't concern yourself with isdn4k-utils.
 
 o  Gnu C                  3.2                     # gcc --version
 o  Gnu make               3.80                    # make --version
@@ -114,12 +107,12 @@ Ksymoops
 
 If the unthinkable happens and your kernel oopses, you may need the
 ksymoops tool to decode it, but in most cases you don't.
-In the 2.6 kernel it is generally preferred to build the kernel with
-CONFIG_KALLSYMS so that it produces readable dumps that can be used as-is
-(this also produces better output than ksymoops).
-If for some reason your kernel is not build with CONFIG_KALLSYMS and
-you have no way to rebuild and reproduce the Oops with that option, then
-you can still decode that Oops with ksymoops.
+It is generally preferred to build the kernel with CONFIG_KALLSYMS so
+that it produces readable dumps that can be used as-is (this also
+produces better output than ksymoops).  If for some reason your kernel
+is not build with CONFIG_KALLSYMS and you have no way to rebuild and
+reproduce the Oops with that option, then you can still decode that Oops
+with ksymoops.
 
 Module-Init-Tools
 -----------------
@@ -261,8 +254,8 @@ needs to be recompiled or (preferably) upgraded.
 NFS-utils
 ---------
 
-In 2.4 and earlier kernels, the nfs server needed to know about any
-client that expected to be able to access files via NFS.  This
+In ancient (2.4 and earlier) kernels, the nfs server needed to know
+about any client that expected to be able to access files via NFS.  This
 information would be given to the kernel by "mountd" when the client
 mounted the filesystem, or by "exportfs" at system startup.  exportfs
 would take information about active clients from /var/lib/nfs/rmtab.
@@ -272,11 +265,11 @@ which is not always easy, particularly when trying to implement
 fail-over.  Even when the system is working well, rmtab suffers from
 getting lots of old entries that never get removed.
 
-With 2.6 we have the option of having the kernel tell mountd when it
-gets a request from an unknown host, and mountd can give appropriate
-export information to the kernel.  This removes the dependency on
-rmtab and means that the kernel only needs to know about currently
-active clients.
+With modern kernels we have the option of having the kernel tell mountd
+when it gets a request from an unknown host, and mountd can give
+appropriate export information to the kernel.  This removes the
+dependency on rmtab and means that the kernel only needs to know about
+currently active clients.
 
 To enable this new functionality, you need to:
 
diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle
index 58b0bf9..fa6e25b 100644
--- a/Documentation/CodingStyle
+++ b/Documentation/CodingStyle
@@ -680,8 +680,8 @@ ones already enabled by DEBUG.
 		Chapter 14: Allocating memory
 
 The kernel provides the following general purpose memory allocators:
-kmalloc(), kzalloc(), kcalloc(), and vmalloc().  Please refer to the API
-documentation for further information about them.
+kmalloc(), kzalloc(), kcalloc(), vmalloc(), and vzalloc().  Please refer to
+the API documentation for further information about them.
 
 The preferred form for passing a size of a struct is the following:
 
diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt
index cd45c8e..84f0a15 100644
--- a/Documentation/cgroups/blkio-controller.txt
+++ b/Documentation/cgroups/blkio-controller.txt
@@ -77,7 +77,7 @@ Throttling/Upper Limit policy
 - Specify a bandwidth rate on particular device for root group. The format
   for policy is "<major>:<minor>  <byes_per_second>".
 
-        echo "8:16  1048576" > /sys/fs/cgroup/blkio/blkio.read_bps_device
+        echo "8:16  1048576" > /sys/fs/cgroup/blkio/blkio.throttle.read_bps_device
 
   Above will put a limit of 1MB/second on reads happening for root group
   on device having major/minor number 8:16.
@@ -90,7 +90,7 @@ Throttling/Upper Limit policy
         1024+0 records out
         4194304 bytes (4.2 MB) copied, 4.0001 s, 1.0 MB/s
 
- Limits for writes can be put using blkio.write_bps_device file.
+ Limits for writes can be put using blkio.throttle.write_bps_device file.
 
 Hierarchical Cgroups
 ====================
@@ -286,28 +286,28 @@ Throttling/Upper limit policy files
 	  specified in bytes per second. Rules are per deivce. Following is
 	  the format.
 
-  echo "<major>:<minor>  <rate_bytes_per_second>" > /cgrp/blkio.read_bps_device
+  echo "<major>:<minor>  <rate_bytes_per_second>" > /cgrp/blkio.throttle.read_bps_device
 
 - blkio.throttle.write_bps_device
 	- Specifies upper limit on WRITE rate to the device. IO rate is
 	  specified in bytes per second. Rules are per deivce. Following is
 	  the format.
 
-  echo "<major>:<minor>  <rate_bytes_per_second>" > /cgrp/blkio.write_bps_device
+  echo "<major>:<minor>  <rate_bytes_per_second>" > /cgrp/blkio.throttle.write_bps_device
 
 - blkio.throttle.read_iops_device
 	- Specifies upper limit on READ rate from the device. IO rate is
 	  specified in IO per second. Rules are per deivce. Following is
 	  the format.
 
-  echo "<major>:<minor>  <rate_io_per_second>" > /cgrp/blkio.read_iops_device
+  echo "<major>:<minor>  <rate_io_per_second>" > /cgrp/blkio.throttle.read_iops_device
 
 - blkio.throttle.write_iops_device
 	- Specifies upper limit on WRITE rate to the device. IO rate is
 	  specified in io per second. Rules are per deivce. Following is
 	  the format.
 
-  echo "<major>:<minor>  <rate_io_per_second>" > /cgrp/blkio.write_iops_device
+  echo "<major>:<minor>  <rate_io_per_second>" > /cgrp/blkio.throttle.write_iops_device
 
 Note: If both BW and IOPS rules are specified for a device, then IO is
       subjectd to both the constraints.
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 72e2384..b1c921c 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -583,3 +583,25 @@ Why:	Superseded by the UVCIOC_CTRL_QUERY ioctl.
 Who:	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 
 ----------------------------
+
+What:	For VIDIOC_S_FREQUENCY the type field must match the device node's type.
+	If not, return -EINVAL.
+When:	3.2
+Why:	It makes no sense to switch the tuner to radio mode by calling
+	VIDIOC_S_FREQUENCY on a video node, or to switch the tuner to tv mode by
+	calling VIDIOC_S_FREQUENCY on a radio node. This is the first step of a
+	move to more consistent handling of tv and radio tuners.
+Who:	Hans Verkuil <hans.verkuil@cisco.com>
+
+----------------------------
+
+What:	Opening a radio device node will no longer automatically switch the
+	tuner mode from tv to radio.
+When:	3.3
+Why:	Just opening a V4L device should not change the state of the hardware
+	like that. It's very unexpected and against the V4L spec. Instead, you
+	switch to radio mode by calling VIDIOC_S_FREQUENCY. This is the second
+	and last step of the move to consistent handling of tv and radio tuners.
+Who:	Hans Verkuil <hans.verkuil@cisco.com>
+
+----------------------------
diff --git a/Documentation/filesystems/caching/netfs-api.txt b/Documentation/filesystems/caching/netfs-api.txt
index a167ab8..7cc6bf2 100644
--- a/Documentation/filesystems/caching/netfs-api.txt
+++ b/Documentation/filesystems/caching/netfs-api.txt
@@ -673,6 +673,22 @@ storage request to complete, or it may attempt to cancel the storage request -
 in which case the page will not be stored in the cache this time.
 
 
+BULK INODE PAGE UNCACHE
+-----------------------
+
+A convenience routine is provided to perform an uncache on all the pages
+attached to an inode.  This assumes that the pages on the inode correspond on a
+1:1 basis with the pages in the cache.
+
+	void fscache_uncache_all_inode_pages(struct fscache_cookie *cookie,
+					     struct inode *inode);
+
+This takes the netfs cookie that the pages were cached with and the inode that
+the pages are attached to.  This function will wait for pages to finish being
+written to the cache and for the cache to finish with the page generally.  No
+error is returned.
+
+
 ==========================
 INDEX AND DATA FILE UPDATE
 ==========================
diff --git a/Documentation/hwmon/f71882fg b/Documentation/hwmon/f71882fg
index 84d2623..de91c0d 100644
--- a/Documentation/hwmon/f71882fg
+++ b/Documentation/hwmon/f71882fg
@@ -22,6 +22,10 @@ Supported chips:
     Prefix: 'f71869'
     Addresses scanned: none, address read from Super I/O config space
     Datasheet: Available from the Fintek website
+  * Fintek F71869A
+    Prefix: 'f71869a'
+    Addresses scanned: none, address read from Super I/O config space
+    Datasheet: Not public
   * Fintek F71882FG and F71883FG
     Prefix: 'f71882fg'
     Addresses scanned: none, address read from Super I/O config space
diff --git a/Documentation/hwmon/k10temp b/Documentation/hwmon/k10temp
index 0393c89..a10f736 100644
--- a/Documentation/hwmon/k10temp
+++ b/Documentation/hwmon/k10temp
@@ -9,8 +9,8 @@ Supported chips:
   Socket S1G3: Athlon II, Sempron, Turion II
 * AMD Family 11h processors:
   Socket S1G2: Athlon (X2), Sempron (X2), Turion X2 (Ultra)
-* AMD Family 12h processors: "Llano"
-* AMD Family 14h processors: "Brazos" (C/E/G-Series)
+* AMD Family 12h processors: "Llano" (E2/A4/A6/A8-Series)
+* AMD Family 14h processors: "Brazos" (C/E/G/Z-Series)
 * AMD Family 15h processors: "Bulldozer"
 
   Prefix: 'k10temp'
@@ -20,12 +20,16 @@ Supported chips:
     http://support.amd.com/us/Processor_TechDocs/31116.pdf
   BIOS and Kernel Developer's Guide (BKDG) for AMD Family 11h Processors:
     http://support.amd.com/us/Processor_TechDocs/41256.pdf
+  BIOS and Kernel Developer's Guide (BKDG) for AMD Family 12h Processors:
+    http://support.amd.com/us/Processor_TechDocs/41131.pdf
   BIOS and Kernel Developer's Guide (BKDG) for AMD Family 14h Models 00h-0Fh Processors:
     http://support.amd.com/us/Processor_TechDocs/43170.pdf
   Revision Guide for AMD Family 10h Processors:
     http://support.amd.com/us/Processor_TechDocs/41322.pdf
   Revision Guide for AMD Family 11h Processors:
     http://support.amd.com/us/Processor_TechDocs/41788.pdf
+  Revision Guide for AMD Family 12h Processors:
+    http://support.amd.com/us/Processor_TechDocs/44739.pdf
   Revision Guide for AMD Family 14h Models 00h-0Fh Processors:
     http://support.amd.com/us/Processor_TechDocs/47534.pdf
   AMD Family 11h Processor Power and Thermal Data Sheet for Notebooks:
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index fd248a31..aa47be7 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2015,6 +2015,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 				the default.
 				off: Turn ECRC off
 				on: Turn ECRC on.
+		realloc		reallocate PCI resources if allocations done by BIOS
+				are erroneous.
 
 	pcie_aspm=	[PCIE] Forcibly enable or disable PCIe Active State Power
 			Management.
diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt
index 1565eefd..6181548 100644
--- a/Documentation/laptops/thinkpad-acpi.txt
+++ b/Documentation/laptops/thinkpad-acpi.txt
@@ -534,6 +534,8 @@ Events that are never propagated by the driver:
 0x2404		System is waking up from hibernation to undock
 0x2405		System is waking up from hibernation to eject bay
 0x5010		Brightness level changed/control event
+0x6000		KEYBOARD: Numlock key pressed
+0x6005		KEYBOARD: Fn key pressed (TO BE VERIFIED)
 
 Events that are propagated by the driver to userspace:
 
@@ -545,6 +547,8 @@ Events that are propagated by the driver to userspace:
 0x3006		Bay hotplug request (hint to power up SATA link when
 		the optical drive tray is ejected)
 0x4003		Undocked (see 0x2x04), can sleep again
+0x4010		Docked into hotplug port replicator (non-ACPI dock)
+0x4011		Undocked from hotplug port replicator (non-ACPI dock)
 0x500B		Tablet pen inserted into its storage bay
 0x500C		Tablet pen removed from its storage bay
 0x6011		ALARM: battery is too hot
@@ -552,6 +556,7 @@ Events that are propagated by the driver to userspace:
 0x6021		ALARM: a sensor is too hot
 0x6022		ALARM: a sensor is extremely hot
 0x6030		System thermal table changed
+0x6040		Nvidia Optimus/AC adapter related (TO BE VERIFIED)
 
 Battery nearly empty alarms are a last resort attempt to get the
 operating system to hibernate or shutdown cleanly (0x2313), or shutdown
diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt
index 8888083..64565aa 100644
--- a/Documentation/power/devices.txt
+++ b/Documentation/power/devices.txt
@@ -520,59 +520,20 @@ Support for power domains is provided through the pwr_domain field of struct
 device.  This field is a pointer to an object of type struct dev_power_domain,
 defined in include/linux/pm.h, providing a set of power management callbacks
 analogous to the subsystem-level and device driver callbacks that are executed
-for the given device during all power transitions, in addition to the respective
-subsystem-level callbacks.  Specifically, the power domain "suspend" callbacks
-(i.e. ->runtime_suspend(), ->suspend(), ->freeze(), ->poweroff(), etc.) are
-executed after the analogous subsystem-level callbacks, while the power domain
-"resume" callbacks (i.e. ->runtime_resume(), ->resume(), ->thaw(), ->restore,
-etc.) are executed before the analogous subsystem-level callbacks.  Error codes
-returned by the "suspend" and "resume" power domain callbacks are ignored.
-
-Power domain ->runtime_idle() callback is executed before the subsystem-level
-->runtime_idle() callback and the result returned by it is not ignored.  Namely,
-if it returns error code, the subsystem-level ->runtime_idle() callback will not
-be called and the helper function rpm_idle() executing it will return error
-code.  This mechanism is intended to help platforms where saving device state
-is a time consuming operation and should only be carried out if all devices
-in the power domain are idle, before turning off the shared power resource(s).
-Namely, the power domain ->runtime_idle() callback may return error code until
-the pm_runtime_idle() helper (or its asychronous version) has been called for
-all devices in the power domain (it is recommended that the returned error code
-be -EBUSY in those cases), preventing the subsystem-level ->runtime_idle()
-callback from being run prematurely.
-
-The support for device power domains is only relevant to platforms needing to
-use the same subsystem-level (e.g. platform bus type) and device driver power
-management callbacks in many different power domain configurations and wanting
-to avoid incorporating the support for power domains into the subsystem-level
-callbacks.  The other platforms need not implement it or take it into account
-in any way.
-
-
-System Devices
---------------
-System devices (sysdevs) follow a slightly different API, which can be found in
-
-	include/linux/sysdev.h
-	drivers/base/sys.c
-
-System devices will be suspended with interrupts disabled, and after all other
-devices have been suspended.  On resume, they will be resumed before any other
-devices, and also with interrupts disabled.  These things occur in special
-"sysdev_driver" phases, which affect only system devices.
-
-Thus, after the suspend_noirq (or freeze_noirq or poweroff_noirq) phase, when
-the non-boot CPUs are all offline and IRQs are disabled on the remaining online
-CPU, then a sysdev_driver.suspend phase is carried out, and the system enters a
-sleep state (or a system image is created).  During resume (or after the image
-has been created or loaded) a sysdev_driver.resume phase is carried out, IRQs
-are enabled on the only online CPU, the non-boot CPUs are enabled, and the
-resume_noirq (or thaw_noirq or restore_noirq) phase begins.
-
-Code to actually enter and exit the system-wide low power state sometimes
-involves hardware details that are only known to the boot firmware, and
-may leave a CPU running software (from SRAM or flash memory) that monitors
-the system and manages its wakeup sequence.
+for the given device during all power transitions, instead of the respective
+subsystem-level callbacks.  Specifically, if a device's pm_domain pointer is
+not NULL, the ->suspend() callback from the object pointed to by it will be
+executed instead of its subsystem's (e.g. bus type's) ->suspend() callback and
+anlogously for all of the remaining callbacks.  In other words, power management
+domain callbacks, if defined for the given device, always take precedence over
+the callbacks provided by the device's subsystem (e.g. bus type).
+
+The support for device power management domains is only relevant to platforms
+needing to use the same device driver power management callbacks in many
+different power domain configurations and wanting to avoid incorporating the
+support for power domains into subsystem-level callbacks, for example by
+modifying the platform bus type.  Other platforms need not implement it or take
+it into account in any way.
 
 
 Device Low Power (suspend) States
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 654097b..b24875b 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -501,13 +501,29 @@ helper functions described in Section 4.  In that case, pm_runtime_resume()
 should be used.  Of course, for this purpose the device's run-time PM has to be
 enabled earlier by calling pm_runtime_enable().
 
-If the device bus type's or driver's ->probe() or ->remove() callback runs
+If the device bus type's or driver's ->probe() callback runs
 pm_runtime_suspend() or pm_runtime_idle() or their asynchronous counterparts,
 they will fail returning -EAGAIN, because the device's usage counter is
-incremented by the core before executing ->probe() and ->remove().  Still, it
-may be desirable to suspend the device as soon as ->probe() or ->remove() has
-finished, so the PM core uses pm_runtime_idle_sync() to invoke the
-subsystem-level idle callback for the device at that time.
+incremented by the driver core before executing ->probe().  Still, it may be
+desirable to suspend the device as soon as ->probe() has finished, so the driver
+core uses pm_runtime_put_sync() to invoke the subsystem-level idle callback for
+the device at that time.
+
+Moreover, the driver core prevents runtime PM callbacks from racing with the bus
+notifier callback in __device_release_driver(), which is necessary, because the
+notifier is used by some subsystems to carry out operations affecting the
+runtime PM functionality.  It does so by calling pm_runtime_get_sync() before
+driver_sysfs_remove() and the BUS_NOTIFY_UNBIND_DRIVER notifications.  This
+resumes the device if it's in the suspended state and prevents it from
+being suspended again while those routines are being executed.
+
+To allow bus types and drivers to put devices into the suspended state by
+calling pm_runtime_suspend() from their ->remove() routines, the driver core
+executes pm_runtime_put_sync() after running the BUS_NOTIFY_UNBIND_DRIVER
+notifications in __device_release_driver().  This requires bus types and
+drivers to make their ->remove() callbacks avoid races with runtime PM directly,
+but also it allows of more flexibility in the handling of devices during the
+removal of their drivers.
 
 The user space can effectively disallow the driver of the device to power manage
 it at run time by changing the value of its /sys/devices/.../power/control
@@ -566,11 +582,6 @@ to do this is:
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);
 
-The PM core always increments the run-time usage counter before calling the
-->prepare() callback and decrements it after calling the ->complete() callback.
-Hence disabling run-time PM temporarily like this will not cause any run-time
-suspend callbacks to be lost.
-
 7. Generic subsystem callbacks
 
 Subsystems may wish to conserve code space by using the set of generic power
diff --git a/Documentation/spinlocks.txt b/Documentation/spinlocks.txt
index 2e3c64b..9dbe885 100644
--- a/Documentation/spinlocks.txt
+++ b/Documentation/spinlocks.txt
@@ -13,18 +13,8 @@ static DEFINE_SPINLOCK(xxx_lock);
 The above is always safe. It will disable interrupts _locally_, but the
 spinlock itself will guarantee the global lock, so it will guarantee that
 there is only one thread-of-control within the region(s) protected by that
-lock. This works well even under UP. The above sequence under UP
-essentially is just the same as doing
-
-	unsigned long flags;
-
-	save_flags(flags); cli();
-	 ... critical section ...
-	restore_flags(flags);
-
-so the code does _not_ need to worry about UP vs SMP issues: the spinlocks
-work correctly under both (and spinlocks are actually more efficient on
-architectures that allow doing the "save_flags + cli" in one operation).
+lock. This works well even under UP also, so the code does _not_ need to
+worry about UP vs SMP issues: the spinlocks work correctly under both.
 
    NOTE! Implications of spin_locks for memory are further described in:
 
@@ -36,27 +26,7 @@ The above is usually pretty simple (you usually need and want only one
 spinlock for most things - using more than one spinlock can make things a
 lot more complex and even slower and is usually worth it only for
 sequences that you _know_ need to be split up: avoid it at all cost if you
-aren't sure). HOWEVER, it _does_ mean that if you have some code that does
-
-	cli();
-	.. critical section ..
-	sti();
-
-and another sequence that does
-
-	spin_lock_irqsave(flags);
-	.. critical section ..
-	spin_unlock_irqrestore(flags);
-
-then they are NOT mutually exclusive, and the critical regions can happen
-at the same time on two different CPU's. That's fine per se, but the
-critical regions had better be critical for different things (ie they
-can't stomp on each other).
-
-The above is a problem mainly if you end up mixing code - for example the
-routines in ll_rw_block() tend to use cli/sti to protect the atomicity of
-their actions, and if a driver uses spinlocks instead then you should
-think about issues like the above.
+aren't sure).
 
 This is really the only really hard part about spinlocks: once you start
 using spinlocks they tend to expand to areas you might not have noticed
@@ -120,11 +90,10 @@ Lesson 3: spinlocks revisited.
 
 The single spin-lock primitives above are by no means the only ones. They
 are the most safe ones, and the ones that work under all circumstances,
-but partly _because_ they are safe they are also fairly slow. They are
-much faster than a generic global cli/sti pair, but slower than they'd
-need to be, because they do have to disable interrupts (which is just a
-single instruction on a x86, but it's an expensive one - and on other
-architectures it can be worse).
+but partly _because_ they are safe they are also fairly slow. They are slower
+than they'd need to be, because they do have to disable interrupts
+(which is just a single instruction on a x86, but it's an expensive one -
+and on other architectures it can be worse).
 
 If you have a case where you have to protect a data structure across
 several CPU's and you want to use spinlocks you can potentially use
diff --git a/Documentation/usb/error-codes.txt b/Documentation/usb/error-codes.txt
index d83703e..b3f606b 100644
--- a/Documentation/usb/error-codes.txt
+++ b/Documentation/usb/error-codes.txt
@@ -76,6 +76,13 @@ A transfer's actual_length may be positive even when an error has been
 reported.  That's because transfers often involve several packets, so that
 one or more packets could finish before an error stops further endpoint I/O.
 
+For isochronous URBs, the urb status value is non-zero only if the URB is
+unlinked, the device is removed, the host controller is disabled, or the total
+transferred length is less than the requested length and the URB_SHORT_NOT_OK
+flag is set.  Completion handlers for isochronous URBs should only see
+urb->status set to zero, -ENOENT, -ECONNRESET, -ESHUTDOWN, or -EREMOTEIO.
+Individual frame descriptor status fields may report more status codes.
+
 
 0			Transfer completed successfully
 
@@ -132,7 +139,7 @@ one or more packets could finish before an error stops further endpoint I/O.
 			device removal events immediately.
 
 -EXDEV			ISO transfer only partially completed
-			look at individual frame status for details
+			(only set in iso_frame_desc[n].status, not urb->status)
 
 -EINVAL			ISO madness, if this happens: Log off and go home