Introduce new tracepoints to the USB core to improve debuggability of
USB device lifecycle events.
The following tracepoints are added:
- usb_alloc_dev: Triggered when a new USB device structure is allocated,
providing insights into early device setup.
- usb_set_device_state: Triggered when the USB device state changes,
allowing observation of the device's state transitions.
These tracepoints capture detailed information about the USB device,
including its name, speed, state, bus current value, and authorized
flag. This will aid developers in diagnosing issues related to device
enumeration within the USB subsystem.
Examples:
usb_alloc_dev: usb 1-1 speed UNKNOWN state attached 0mA [authorized]
usb_set_device_state: usb 1-1 speed UNKNOWN state powered 0mA [authorized]
usb_set_device_state: usb 1-1 speed full-speed state default 500mA [authorized]
usb_set_device_state: usb 1-1 speed full-speed state default 500mA [authorized]
usb_set_device_state: usb 1-1 speed full-speed state addressed 500mA [authorized]
usb_set_device_state: usb 1-1 speed full-speed state configured 500mA [authorized]
usb_set_device_state: usb 1-1 speed full-speed state suspended 500mA [authorized]
usb_set_device_state: usb 1-1 speed full-speed state not attached 500mA [authorized]
Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://patch.msgid.link/20251015-usbcore-tracing-v2-2-5a14b5b9d4e0@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This will add usb_alloc_noncoherent() and usb_free_noncoherent()
functions to support alloc and free buffer in a dma-noncoherent way.
To explicit manage the memory ownership for the kernel and device,
this will also add usb_dma_noncoherent_sync_for_cpu/device() functions
and call it at proper time. The management requires the user save
sg_table returned by usb_alloc_noncoherent() to urb->sgt.
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20250704095751.73765-2-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When creating a device path in the driver the snprintf() takes
up to 16 characters long argument along with the additional up to
12 characters for the signed integer (as it can't see the actual limits)
and tries to pack this into 16 bytes array. GCC complains about that
when build with `make W=1`:
drivers/usb/core/usb.c:705:25: note: ‘snprintf’ output between 3 and 28 bytes into a destination of size 16
Since everything works until now, let's just check for the potential
buffer overflow and bail out. It is most likely a never happen situation,
but at least it makes GCC happy.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250321164949.423957-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With ARCH=x86, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/core/usbcore.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/mon/usbmon.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/class/usbtmc.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/storage/uas.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/chipidea/ci_hdrc_msm.o
Add the missing invocations of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240618-md-drivers-usb-v2-1-e9b20a5eb7f9@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is usbdrv_wrap in struct usb_driver and usb_device_driver, it
contains device_driver and for_devices. for_devices is used to
distinguish between device drivers and interface drivers.
Like the is_usb_device(), it tests the type of the device. We can test
that if the probe of device_driver is equal to usb_probe_device in
is_usb_device_driver(), and then the struct usbdrv_wrap is no longer
needed.
Clean up struct usbdrv_wrap, use device_driver directly in struct
usb_driver and usb_device_driver. This makes the code cleaner.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20240104032822.1896596-1-yajun.deng@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Wireless USB has long been defunct, and kernel support for it was
removed in 2020 by commit caa6772db4 ("Staging: remove wusbcore and
UWB from the kernel tree.").
Nevertheless, some vestiges of the old implementation still clutter up
the USB subsystem and one or two other places. Let's get rid of them
once and for all.
The only parts still left are the user-facing APIs in
include/uapi/linux/usb/ch9.h. (There are also a couple of misleading
instances, such as the Sierra Wireless USB modem, which is a USB modem
made by Sierra Wireless.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/b4f2710f-a2de-4fb0-b50f-76776f3a961b@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Acked-by: Herve Codina <herve.codina@bootlin.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230718143027.1064731-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that the driver core allows for struct class to be in read-only
memory, remove the usb_class structure and create the usbmisc_class
const class structure declared at build time which places it into
read-only memory, instead of having it to be dynamically allocated
at load time.
Additionally, now we register usb class at startup and unregister it
when shutting down, so we don't have to count uses of the class.
Therefore we don't need the 'usb_class' structure anymore. Due to this
fact, remove all static functions related to class initialization and
deinitialization. We can't use them in 'usb.c' since they are static
and we don't really need them anymore.
Since we have to register the class in usb_init function in 'usb.c'
and use it in 'file.c' as well, declare the usbmisc_class structure
as 'export' in the 'usb.h' file.
Debatable moment: the class registration and unregistration functions
could be extracted to the 'file.c'. I think we don't want to do this
since it would be one-line functions. They would make the code paths
more confusing and add calling overhead.
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230621202514.1223670-1-ivan.orlov0322@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Many of the older USB drivers in the Linux USB stack were written
based simply on a vendor's device specification. They use the
endpoint information in the spec and assume these endpoints will
always be present, with the properties listed, in any device matching
the given vendor and product IDs.
While that may have been true back then, with spoofing and fuzzing it
is not true any more. More and more we are finding that those old
drivers need to perform at least a minimum of checking before they try
to use any endpoint other than ep0.
To make this checking as simple as possible, we now add a couple of
utility routines to the USB core. usb_check_bulk_endpoints() and
usb_check_int_endpoints() take an interface pointer together with a
list of endpoint addresses (numbers and directions). They check that
the interface's current alternate setting includes endpoints with
those addresses and that each of these endpoints has the right type:
bulk or interrupt, respectively.
Although we already have usb_find_common_endpoints() and related
routines meant for a similar purpose, they are not well suited for
this kind of checking. Those routines find endpoints of various
kinds, but only one (either the first or the last) of each kind, and
they don't verify that the endpoints' addresses agree with what the
caller expects.
In theory the new routines could be more general: They could take a
particular altsetting as their argument instead of always using the
interface's current altsetting. In practice I think this won't matter
too much; multiple altsettings tend to be used for transferring media
(audio or visual) over isochronous endpoints, not bulk or interrupt.
Drivers for such devices will generally require more sophisticated
checking than these simplistic routines provide.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/dd2c8e8c-2c87-44ea-ba17-c64b97e201c9@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core updates from Greg KH:
"Here is the large set of driver core changes for 6.3-rc1.
There's a lot of changes this development cycle, most of the work
falls into two different categories:
- fw_devlink fixes and updates. This has gone through numerous review
cycles and lots of review and testing by lots of different devices.
Hopefully all should be good now, and Saravana will be keeping a
watch for any potential regression on odd embedded systems.
- driver core changes to work to make struct bus_type able to be
moved into read-only memory (i.e. const) The recent work with Rust
has pointed out a number of areas in the driver core where we are
passing around and working with structures that really do not have
to be dynamic at all, and they should be able to be read-only
making things safer overall. This is the contuation of that work
(started last release with kobject changes) in moving struct
bus_type to be constant. We didn't quite make it for this release,
but the remaining patches will be finished up for the release after
this one, but the groundwork has been laid for this effort.
Other than that we have in here:
- debugfs memory leak fixes in some subsystems
- error path cleanups and fixes for some never-able-to-be-hit
codepaths.
- cacheinfo rework and fixes
- Other tiny fixes, full details are in the shortlog
All of these have been in linux-next for a while with no reported
problems"
[ Geert Uytterhoeven points out that that last sentence isn't true, and
that there's a pending report that has a fix that is queued up - Linus ]
* tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits)
debugfs: drop inline constant formatting for ERR_PTR(-ERROR)
OPP: fix error checking in opp_migrate_dentry()
debugfs: update comment of debugfs_rename()
i3c: fix device.h kernel-doc warnings
dma-mapping: no need to pass a bus_type into get_arch_dma_ops()
driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place
Revert "driver core: add error handling for devtmpfs_create_node()"
Revert "devtmpfs: add debug info to handle()"
Revert "devtmpfs: remove return value of devtmpfs_delete_node()"
driver core: cpu: don't hand-override the uevent bus_type callback.
devtmpfs: remove return value of devtmpfs_delete_node()
devtmpfs: add debug info to handle()
driver core: add error handling for devtmpfs_create_node()
driver core: bus: update my copyright notice
driver core: bus: add bus_get_dev_root() function
driver core: bus: constify bus_unregister()
driver core: bus: constify some internal functions
driver core: bus: constify bus_get_kset()
driver core: bus: constify bus_register/unregister_notifier()
driver core: remove private pointer from struct bus_type
...
The kerneldoc for usb_get_dev() and usb_get_intf() says that drivers
should always refcount the references they hold for the usb_device or
usb_interface structure, respectively. But this is an overstatement:
In many cases drivers do not access these references after they have
been unbound, and in such cases refcounting is unnecessary.
This patch updates the kerneldoc for the two routines, explaining when
a driver does not need to increment and decrement the refcount. This
should help dispel misconceptions which might otherwise afflict
programmers new to the USB subsystem.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/Yhjp4Rp9Alipmwtq@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB devices cannot perform DMA and hence have no dma_mask set in their
device structure. Therefore importing dmabuf into a USB-based driver
fails, which breaks joining and mirroring of display in X11.
For USB devices, pick the associated USB controller as attachment device.
This allows the DRM import helpers to perform the DMA setup. If the DMA
controller does not support DMA transfers, we're out of luck and cannot
import. Our current USB-based DRM drivers don't use DMA, so the actual
DMA device is not important.
Tested by joining/mirroring displays of udl and radeon under Gnome/X11.
v8:
* release dmadev if device initialization fails (Noralf)
* fix commit description (Noralf)
v7:
* fix use-before-init bug in gm12u320 (Dan)
v6:
* implement workaround in DRM drivers and hold reference to
DMA device while USB device is in use
* remove dev_is_usb() (Greg)
* collapse USB helper into usb_intf_get_dma_device() (Alan)
* integrate Daniel's TODO statement (Daniel)
* fix typos (Greg)
v5:
* provide a helper for USB interfaces (Alan)
* add FIXME item to documentation and TODO list (Daniel)
v4:
* implement workaround with USB helper functions (Greg)
* use struct usb_device->bus->sysdev as DMA device (Takashi)
v3:
* drop gem_create_object
* use DMA mask of USB controller, if any (Daniel, Christian, Noralf)
v2:
* move fix to importer side (Christian, Daniel)
* update SHMEM and CMA helpers for new PRIME callbacks
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 6eb0233ec2 ("usb: don't inherity DMA properties for USB devices")
Tested-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210303133229.3288-1-tzimmermann@suse.de
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
The usage of in_interrupt() in drivers is phased out for various reasons.
Various comments use !in_interrupt() to describe calling context for
functions which might sleep. That's wrong because the calling context has
to be preemptible task context, which is not what !in_interrupt()
describes.
Replace !in_interrupt() with more accurate plain text descriptions.
The comment for usb_hcd_poll_rh_status() is misleading as this function is
called from all kinds of contexts including preemptible task
context. Remove it as there is obviously no restriction.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-usb@vger.kernel.org
Link: https://lore.kernel.org/r/20201019101110.851821025@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As the comment in usb_alloc_dev correctly states, drivers can't use
the DMA API on usb device, and at least calling dma_set_mask on them
is highly dangerous. Unlike what the comment states upper level drivers
also can't really use the presence of a dma mask to check for DMA
support, as the dma_mask is set by default for most busses.
Setting the dma_mask comes from "[PATCH] usbcore dma updates (and doc)"
in BitKeeper times, as it seems like it was primarily for setting the
NETIF_F_HIGHDMA flag in USB drivers, something that has long been
fixed up since.
Setting the dma_pfn_offset comes from commit b44bbc46a8
("usb: core: setup dma_pfn_offset for USB devices and, interfaces"),
which worked around the fact that the scsi_calculate_bounce_limits
functions wasn't going through the proper driver interface to query
DMA information, but that function was removed in commit 21e07dba9f
("scsi: reduce use of block bounce buffers") years ago.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core and debugfs updates from Greg KH:
"Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse easier
due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of
merge issues that Stephen has been patient with me for"
* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
debugfs: make error message a bit more verbose
orangefs: fix build warning from debugfs cleanup patch
ubifs: fix build warning after debugfs cleanup patch
driver: core: Allow subsystems to continue deferring probe
drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
arch_topology: Remove error messages on out-of-memory conditions
lib: notifier-error-inject: no need to check return value of debugfs_create functions
swiotlb: no need to check return value of debugfs_create functions
ceph: no need to check return value of debugfs_create functions
sunrpc: no need to check return value of debugfs_create functions
ubifs: no need to check return value of debugfs_create functions
orangefs: no need to check return value of debugfs_create functions
nfsd: no need to check return value of debugfs_create functions
lib: 842: no need to check return value of debugfs_create functions
debugfs: provide pr_fmt() macro
debugfs: log errors when something goes wrong
drivers: s390/cio: Fix compilation warning about const qualifiers
drivers: Add generic helper to match by of_node
driver_find_device: Unify the match function with class_find_device()
bus_find_device: Unify the match callback with class_find_device
...
The USB gadget subsystem wants to use the USB debugfs root directory, so
move it to the common "core" USB code so that it is properly initialized
and removed as needed.
In order to properly do this, we need to load the common code before the
usb core code, when everything is linked into the kernel, so reorder the
link order of the code.
Also as the usb common code has the possibility of the led trigger logic
to be merged into it, handle the build option properly by only having
one module init/exit function and have the common code initialize the
led trigger if needed.
Reported-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Tested-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the default autosuspend delay configurable at build time.
This is useful for systems that require a non-standard value as
it avoids relying on the command line being properly set.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On Chrome OS we want to use USBguard to potentially limit access to USB
devices based on policy. We however to do not want to wait for userspace to
come up before initializing fixed USB devices to not regress our boot
times.
This patch adds option to instruct the kernel to only authorize devices
connected to the internal ports. Previously we could either authorize
all or none (or, by default, we'd only authorize wired devices).
The behavior is controlled via usbcore.authorized_default command line
option.
Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb_find_alt_setting() takes a pointer to a struct usb_host_config as
an argument; it searches for an interface with specified interface and
alternate setting numbers in that config. However, it crashes if the
usb_host_config pointer argument is NULL.
Since this is a general-purpose routine, available for use in many
places, we want to to be more robust. This patch makes it return NULL
whenever the config argument is NULL.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: syzbot+19c3aaef85a89d451eac@syzkaller.appspotmail.com
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Cc: Johan Hovold <johan@kernel.org>
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Trying quirks in usbcore needs to rebuild the driver or the entire
kernel if it's builtin. It can save a lot of time if usbcore has similar
ability like "usbhid.quirks=" and "usb-storage.quirks=".
Rename the original quirk detection function to "static" as we introduce
this new "dynamic" function.
Now users can use "usbcore.quirks=" as short term workaround before the
next kernel release. Also, the quirk parameter can XOR the builtin
quirks for debugging purpose.
This is inspired by usbhid and usb-storage.
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Trying quirks in usbcore needs to rebuild the driver or the entire
kernel if it's builtin. It can save a lot of time if usbcore has similar
ability like "usbhid.quirks=" and "usb-storage.quirks=".
Rename the original quirk detection function to "static" as we introduce
this new "dynamic" function.
Now users can use "usbcore.quirks=" as short term workaround before the
next kernel release. Also, the quirk parameter can XOR the builtin
quirks for debugging purpose.
This is inspired by usbhid and usb-storage.
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Clean up the USB device-node helper that is used to look up a device
node given a parent hub device and a port number. Also pass in a struct
usb_device as first argument to provide some type checking.
Give the helper the more descriptive name usb_of_get_device_node(),
which matches the new usb_of_get_interface_node() helper that is used to
look up a second type of of child node from a USB device.
Note that the terms "device node" and "interface node" are defined and
used by the OF Recommended Practice for USB.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To match the rest of the kernel, the SPDX tags for the drivers/usb/core/
files are moved to the first line of the file. This makes it more
obvious the tag is present as well as making it match the other 12k
files in the tree with this location.
It also uses // to match the "expected style" as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In an attempt to work around a pinmux over-allocation issue in driver
core, commit dc5878abf4 ("usb: core: move root hub's device node
assignment after it is added to bus") moved the device-tree node
assignment until after the root hub had been registered.
This not only makes the device-tree node unavailable to the usb driver
during probe, but also prevents the of_node from being linked to in
sysfs and causes a race with user-space for the (recently added) devspec
attribute.
Use the new device_set_of_node_from_dev() helper to reuse the node of
the sysdev device, something which now prevents driver core from trying
to reclaim any pinctrl pins during probe.
Fixes: dc5878abf4 ("usb: core: move root hub's device node assignment after it is added to bus")
Fixes: 51fa91475e ("usb/core: Added devspec sysfs entry for devices behind the usb hub")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure to release any OF device-node reference taken when creating
the USB device.
Note that we currently do not hold a reference to the root hub
device-tree node (i.e. the parent controller node).
Fixes: 69bec72598 ("USB: core: let USB device know device node")
Cc: stable <stable@vger.kernel.org> # v4.6
Acked-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the kerneldoc comment for usb_find_common_endpoints_reverse()
self-contained by adding a full description and removing the reference
to usb_find_common_endpoints().
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Several drivers have implemented their endpoint look-up loops in such a
way that they have picked the last endpoint descriptor of the specified
type should more than one such descriptor exist.
To avoid any regressions, add corresponding helpers to lookup endpoints
by searching the endpoint descriptors in reverse order.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Many USB drivers iterate over the available endpoints to find required
endpoints of a specific type and direction. Typically the endpoints are
required for proper function and a missing endpoint should abort probe.
To facilitate code reuse, add a helper to retrieve common endpoints
(bulk or interrupt, in or out) and four wrappers to find a single
endpoint.
Note that the helpers are marked as __must_check to serve as a reminder
to always verify that all expected endpoints are indeed present. This
also means that any optional endpoints, typically need to be looked up
through separate calls.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some of the USB core files were missing explicit license information.
As all files in the kernel tree are implicitly licensed under the
GPLv2-only, be explicit in case someone get confused looking at
individual files by using the SPDX nomenclature.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
