This patch (as936) updates the kerneldoc for usb_unlink_urb. The
explanation of how endpoint queues are meant to work is now clearer
and in better agreement with reality.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as937) fixes a minor bug in the autosuspend usage-counting
code. Each hub's usage counter keeps track of the number of
unsuspended children. However the current driver increments the
counter after registering a new child, by which time the child may
already have been suspended and caused the counter to go negative.
The obvious solution is to increment the counter before registering
the child.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as934) adds a new readonly binary sysfs attribute file
called "descriptors" for each USB device. The attribute contains the
device descriptor followed by the raw descriptor entry (config plug
subsidiary descriptors) for the current configuration.
Having this information available in fixed-format binary makes life a
lot easier for user programs by avoiding the need to open, read, and
parse multiple sysfs text files.
The information in this attribute file is much like that in usbfs's
device file, but there are some significant differences:
The 2-byte fields in the device descriptor are left in
little-endian byte order, as they appear on the bus and
in the kernel.
Only one raw descriptor set is presented, that of the
current configuration.
Opening this file will not cause a suspended device to be
autoresumed.
The last item in particular should be a big selling point for libusb,
which currently forces all USB devices to be resumed as it scans the
device tree.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Dave Mielke <dave@mielke.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This defines a dev_vdbg() call, which is enabled with -DVERBOSE_DEBUG.
When enabled, dev_vdbg() acts just like dev_dbg(). When disabled, it is a
NOP ... just like dev_dbg() without -DDEBUG. The specific code was moved
out of a USB patch, but lots of drivers have similar support.
That is, code can now be written to use an additional level of debug
output, selected at compile time. Many driver authors have found this
idiom to be very useful. A typical usage model is for "normal" debug
messages to focus on fault paths and not be very "chatty", so that those
messages can be left on during normal operation without much of a
performance or syslog load. On the other hand "verbose" messages would be
noisy enough that they wouldn't normally be enabled; they might even affect
timings enough to change system or driver behavior.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves. This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.
It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.
The patch causes all kernel threads to be nonfreezable by default (ie. to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE. It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear. Additionally, it updates documentation to
describe the freezing of tasks more accurately.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
this adds some scanners reported to be crashed by autosuspend to
the quirk list.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch updates some of the documentation about DMA buffer management
for USB, and ways to avoid extra copying. Our understanding of the issues
has improved over time.
- Most drivers should *avoid* the dma-coherent allocators. There are
a few exceptions (like the HID driver).
- Some methods are currently commented out; it seems folk writing
USB drivers aren't doing performance tuning at that level yet.
- Just avoid highmem; there's no good way to pass an "I can do highmem
DMA" capability through a driver stack. This is easy, everything
already avoids highmem. But it'd be nice if x86_32 systems with much
physical memory could use it directly with network adapters and mass
storage devices. (Patch, anyone?)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make usb autosuspend timers 1sec jiffy aligned.
This helps to reduce the frequency at which the CPU must be taken out of a
lower-power state.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Blackberry devices charge over USB. By autosuspending the port, they are
not able to charge reliably.
Signed-off-by: Jeremy Katz <katzj@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB_IAD: Adds support for USB Interface Association Descriptors.
This patch adds support to the USB host stack for parsing, storing, and
displaying Interface Association Descriptors. In /proc/bus/usb/devices
lines starting with A: show the fields in an IAD. In sysfs if an
interface on a USB device is referenced by an IAD the following files
will be added to the sysfs directory for that interface:
iad_bFirstInterface, iad_bInterfaceCount, iad_bFunctionClass, and
iad_bFunctionSubClass, iad_bFunctionProtocol
Signed-off-by: Craig W. Nadler <craig@nadler.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The loop in usb_sg_wait() is structured in a way that makes it hard to
tell, when the loop exits, whether or not the last URB submission
succeeded. This patch (as928) changes it from a "for" loop to a
"while" loop and keeps "i" always equal to the number of successful
submissions. This fixes an off-by-one error which can show up when
the first URB submission fails.
The patch also removes a couple of lines that initialize fields which
don't need to be initialized.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Root hubs can't be resumed if their parent controller device is still
suspended. This patch (as925) adds a check for that condition in
hcd_bus_resume() and prevents it from being treated as a fatal
controller failure.
ehci-hcd is updated to add the corresponding test. Unnecessary
debugging messages are removed from uhci-hcd and dummy-hcd. The
error return code from dummy-hcd is changed to -ESHUTDOWN, the same as
the others. ohci-hcd doesn't need any changes.
Suspend handling in the non-PCI host drivers is somewhat hit-and-miss.
This patch shouldn't have any effect on them.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as922) removes all but one of the remaining vestiges of
dev->power.power_state from usbcore. The only usage left must remain
until the deprecated "power/state" sysfs attribute is gone.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB: Add URB_FREE_BUFFER flag for freeing the transfer buffer
In some cases it is not needed that the driver keeps track of the
transfer buffer of an URB. It can be simply freed along with the
URB itself when the reference count goes down to zero. The new
flag URB_FREE_BUFFER enables this behavior.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Many device manufacturers are using full-speed bInterval values in high-speed
interrupt endpoint descriptors. If the bInterval value is greater than 16,
assume the device uses full-speed descriptors and fix the value accordingly.
Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch releases DMA resources if enqueue fails in the HCD.
Linux had this bug ever since we converted from virt_to_bus for 2.4.
It is difficult to hit. A user would need a significant memory pressure
or some other unusual condition.
It was reported to me by IBM. They ran a management application for
RSA II adapters which sent Bulk requests to an Interrupt endpoint.
Submissions got rejected by HCD due to an invalid interval value
and the swiotlb pool became depleted in the matter of hours.
We fixed the invalid interval issue in devio.c separately, but this
seems to be a bug worth fixing as well.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A noticeable number of low-speed devices mistakenly include
descriptors for Bulk endpoints, which is forbidden by the USB spec.
In an attempt to make such devices more usable, this patch (as924)
converts the descriptors to Interrupt with an interval of 1 ms.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as920) adds an extra level of protection to the
USB-Persist facility. Now it will apply by default only to hubs; for
all other devices the user must enable it explicitly by setting the
power/persist device attribute.
The disconnect_all_children() routine in hub.c has been removed and
its code placed inline. This is the way it was originally as part of
hub_pre_reset(); the revised usage in hub_reset_resume() is
sufficiently different that the code can no longer be shared.
Likewise, mark_children_for_reset() is now inline as part of
hub_reset_resume(). The end result looks much cleaner than before.
The sysfs interface is updated to add the new attribute file, and
there are corresponding documentation updates.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as919) unifies the code paths used for normal resume and
for reset-resume. Earlier I had failed to note a section in the USB
spec which requires the host to resume a suspended port before
resetting it if the attached device is enabled for remote wakeup.
Since the port has to be resumed anyway, we might as well reuse the
existing code.
The main changes are:
usb_reset_suspended_device() is eliminated.
usb_root_hub_lost_power() is moved down next to the
hub_reset_resume() routine, to which it is logically
related.
finish_port_resume() does a port reset() if the device's
reset_resume flag is set.
usb_port_resume() doesn't check whether the port is initially
enabled if this is a USB-Persist sort of resume.
Code to perform the port reset is added to the resume pathway
for the non-CONFIG_USB_SUSPEND case.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as918) introduces a new USB driver method: reset_resume.
It is called when a device needs to be reset as part of a resume
procedure (whether because of a device quirk or because of the
USB-Persist facility), thereby taking over a role formerly assigned to
the post_reset method. As a consequence, post_reset no longer needs
an argument indicating whether it is being called as part of a
reset-resume. This separation of functions makes the code clearer.
In addition, the pre_reset and post_reset method return types are
changed; they now must return an error code. The return value is
unused at present, but at some later time we may unbind drivers and
re-probe if they encounter an error during reset handling.
The existing pre_reset and post_reset methods in the usbhid,
usb-storage, and hub drivers are updated to match the new
requirements. For usbhid the post_reset routine is also used for
reset_resume (duplicate method pointers); for the other drivers a new
reset_resume routine is added. The change to hub.c looks bigger than
it really is, because mark_children_for_reset_resume() gets moved down
next to the new hub_reset_resume() routine.
A minor change to usb-storage makes the usb_stor_report_bus_reset()
routine acquire the host lock instead of requiring the caller to hold
it already.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as917) removes a now-unnecessary level of subroutine
nesting from hub.c. Since usb_port_suspend() does nothing but call
hub_port_suspend(), and usb_port_resume() does nothing but call
hub_port_resume(), there's no reason to keep the routines separate.
Also included in the patch are a few cosmetic changes involving
whitespace and use of braces.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as916) completes the separation of code paths for suspend
and resume of root hubs as opposed to non-root devices. Root hubs
will be power-managed through their bus_suspend and bus_resume
methods, whereas normal devices will use usb_port_suspend() and
usb_port_resume().
Changes to the hcd_bus_{suspend,resume} routines mostly represent
motion of code that was already present elsewhere. They include:
Adding debugging log messages,
Setting the device state appropriately, and
Adding a resume recovery time delay.
Changes to the port-suspend and port-resume routines in hub.c include:
Removal of checks for root devices (since they will never
be triggered), and
Removal of checks for NULL or invalid device pointers (these
were left over from earlier kernel versions and aren't needed
at all).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as915b) combines the public routine usb_port_suspend() and
the private routine __usb_port_suspend() into a single function.
By removing the explicit mention of otg_port in the call to
__usb_port_suspend(), we prevent a possible error in which the system
tries to perform HNP on the wrong port when a non-targeted device is
plugged into a non-OTG port.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Alan Stern
David Brownell
Rafael J. Wysocki
Oliver Neukum
Yinghai Lu
Venki Pallipadi
Jeremy Katz
Craig W. Nadler
Marcel Holtmann
Laurent Pinchart
Pete Zaitcev