When building the htmldocs (in verbose mode), scripts/kernel-doc reports the following type of warnings: Warning(drivers/usb/core/usb.c:76): No description found for return value of 'usb_find_alt_setting' Fix them by: - adding some missing descriptions of return values - using "Return" sections for those descriptions Signed-off-by: Yacine Belkadi <yacine.belkadi.1@xxxxxxxxx> --- Applied to b3a3a9c441e2c8f6b6760de9331023a7906a4ac6 drivers/usb/core/buffer.c | 5 ++-- drivers/usb/core/driver.c | 22 ++++++++++++++-- drivers/usb/core/file.c | 2 +- drivers/usb/core/hcd-pci.c | 2 ++ drivers/usb/core/hcd.c | 37 +++++++++++++++++++-------- drivers/usb/core/hub.c | 37 +++++++++++++++++++-------- drivers/usb/core/message.c | 49 ++++++++++++++++++++---------------- drivers/usb/core/urb.c | 34 ++++++++++++++++--------- drivers/usb/core/usb.c | 60 +++++++++++++++++++++++++++----------------- include/linux/usb.h | 12 ++++++--- 10 files changed, 173 insertions(+), 87 deletions(-) diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c index b0585e6..2355974 100644 --- a/drivers/usb/core/buffer.c +++ b/drivers/usb/core/buffer.c @@ -43,10 +43,11 @@ static const size_t pool_max[HCD_BUFFER_POOLS] = { * * Call this as part of initializing a host controller that uses the dma * memory allocators. It initializes some pools of dma-coherent memory that - * will be shared by all drivers using that controller, or returns a negative - * errno value on error. + * will be shared by all drivers using that controller. * * Call hcd_buffer_destroy() to clean up after using those pools. + * + * Return: 0 if successful. A negative errno value otherwise. */ int hcd_buffer_create(struct usb_hcd *hcd) { diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 7609ac4..124bcc5 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -117,6 +117,8 @@ static DRIVER_ATTR(new_id, S_IRUGO | S_IWUSR, show_dynids, store_new_id); * @count: input size * * Removes a dynamic usb device ID from this driver. + * + * Return: @count on success. A negative error code otherwise. */ static ssize_t store_remove_id(struct device_driver *driver, const char *buf, size_t count) @@ -457,6 +459,8 @@ static int usb_unbind_interface(struct device *dev) * Callers must own the device lock, so driver probe() entries don't need * extra locking, but other call contexts may need to explicitly claim that * lock. + * + * Return: 0 on success. */ int usb_driver_claim_interface(struct usb_driver *driver, struct usb_interface *iface, void *priv) @@ -658,6 +662,8 @@ EXPORT_SYMBOL_GPL(usb_match_one_id); * These device tables are exported with MODULE_DEVICE_TABLE, through * modutils, to support the driver loading functionality of USB hotplugging. * + * Return: The first matching usb_device_id, or %NULL. + * * What Matches: * * The "match_flags" element in a usb_device_id controls which @@ -823,7 +829,8 @@ static int usb_uevent(struct device *dev, struct kobj_uevent_env *env) * Registers a USB device driver with the USB core. The list of * unattached devices will be rescanned whenever a new driver is * added, allowing the new driver to attach to any recognized devices. - * Returns a negative error code on failure and 0 on success. + * + * Return: A negative error code on failure and 0 on success. */ int usb_register_device_driver(struct usb_device_driver *new_udriver, struct module *owner) @@ -879,7 +886,8 @@ EXPORT_SYMBOL_GPL(usb_deregister_device_driver); * Registers a USB interface driver with the USB core. The list of * unattached interfaces will be rescanned whenever a new driver is * added, allowing the new driver to attach to any recognized interfaces. - * Returns a negative error code on failure and 0 on success. + * + * Return: A negative error code on failure and 0 on success. * * NOTE: if you want your driver to use the USB major number, you must call * usb_register_dev() to enable that functionality. This function no longer @@ -1213,6 +1221,8 @@ done: * unpredictable times. * * This routine can run only in process context. + * + * Return: 0 if the suspend succeeded. */ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg) { @@ -1294,6 +1304,8 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg) * unpredictable times. * * This routine can run only in process context. + * + * Return: 0 on success. */ static int usb_resume_both(struct usb_device *udev, pm_message_t msg) { @@ -1491,6 +1503,8 @@ void usb_autosuspend_device(struct usb_device *udev) * The caller must hold @udev's device lock. * * This routine can run only in process context. + * + * Return: 0 on success. A negative error code otherwise. */ int usb_autoresume_device(struct usb_device *udev) { @@ -1600,6 +1614,8 @@ EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend); * However if the autoresume fails then the counter is re-decremented. * * This routine can run only in process context. + * + * Return: 0 on success. */ int usb_autopm_get_interface(struct usb_interface *intf) { @@ -1633,6 +1649,8 @@ EXPORT_SYMBOL_GPL(usb_autopm_get_interface); * resumed. * * This routine can run in atomic context. + * + * Return: 0 on success. A negative error code otherwise. */ int usb_autopm_get_interface_async(struct usb_interface *intf) { diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c index 6a4c407..7421888 100644 --- a/drivers/usb/core/file.c +++ b/drivers/usb/core/file.c @@ -153,7 +153,7 @@ void usb_major_cleanup(void) * usb_deregister_dev() must be called when the driver is done with * the minor numbers given out by this function. * - * Returns -EINVAL if something bad happens with trying to register a + * Return: -EINVAL if something bad happens with trying to register a * device, and 0 on success. */ int usb_register_dev(struct usb_interface *intf, diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c index caeb8d6..b9d3c43 100644 --- a/drivers/usb/core/hcd-pci.c +++ b/drivers/usb/core/hcd-pci.c @@ -171,6 +171,8 @@ static void ehci_wait_for_companions(struct pci_dev *pdev, struct usb_hcd *hcd, * through the hotplug entry's driver_data. * * Store this function in the HCD's struct pci_driver as probe(). + * + * Return: 0 if successful. */ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) { diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 014dc99..dc1346f 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -378,9 +378,10 @@ MODULE_PARM_DESC(authorized_default, * @buf: Buffer for USB string descriptor (header + UTF-16LE) * @len: Length (in bytes; may be odd) of descriptor buffer. * - * The return value is the number of bytes filled in: 2 + 2*strlen(s) or - * buflen, whichever is less. + * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len, + * whichever is less. * + * Note: * USB String descriptors can contain at most 126 characters; input * strings longer than that are truncated. */ @@ -416,7 +417,8 @@ ascii2desc(char const *s, u8 *buf, unsigned len) * * Produces either a manufacturer, product or serial number string for the * virtual root hub device. - * Returns the number of bytes filled in: the length of the descriptor or + * + * Return: The number of bytes filled in: the length of the descriptor or * of the provided buffer, whichever is less. */ static unsigned @@ -938,6 +940,8 @@ static void usb_bus_init (struct usb_bus *bus) * * Assigns a bus number, and links the controller into usbcore data * structures so that it can be seen by scanning the bus list. + * + * Return: 0 if successful. A negative error code otherwise. */ static int usb_register_bus(struct usb_bus *bus) { @@ -1002,6 +1006,8 @@ static void usb_deregister_bus (struct usb_bus *bus) * the device properly in the device tree and then calls usb_new_device() * to register the usb device. It also assigns the root hub's USB address * (always 1). + * + * Return: 0 if successful. A negative error code otherwise. */ static int register_root_hub(struct usb_hcd *hcd) { @@ -1108,7 +1114,9 @@ EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume); * @isoc: true for isochronous transactions, false for interrupt ones * @bytecount: how many bytes in the transaction. * - * Returns approximate bus time in nanoseconds for a periodic transaction. + * Return: Approximate bus time in nanoseconds for a periodic transaction. + * + * Note: * See USB 2.0 spec section 5.11.3; only periodic transfers need to be * scheduled in software, this function is only used for such scheduling. */ @@ -1166,7 +1174,7 @@ EXPORT_SYMBOL_GPL(usb_calc_bus_time); * be disabled. The actions carried out here are required for URB * submission, as well as for endpoint shutdown and for usb_kill_urb. * - * Returns 0 for no error, otherwise a negative error code (in which case + * Return: 0 for no error, otherwise a negative error code (in which case * the enqueue() method must fail). If no error occurs but enqueue() fails * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing * the private spinlock and returning. @@ -1221,7 +1229,7 @@ EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep); * be disabled. The actions carried out here are required for making * sure than an unlink is valid. * - * Returns 0 for no error, otherwise a negative error code (in which case + * Return: 0 for no error, otherwise a negative error code (in which case * the dequeue() method must fail). The possible error codes are: * * -EIDRM: @urb was not submitted or has already completed. @@ -1784,7 +1792,7 @@ rescan: * pass in the current alternate interface setting in cur_alt, * and pass in the new alternate interface setting in new_alt. * - * Returns an error if the requested bandwidth change exceeds the + * Return: An error if the requested bandwidth change exceeds the * bus bandwidth or host controller internal resources. */ int usb_hcd_alloc_bandwidth(struct usb_device *udev, @@ -1954,9 +1962,12 @@ void usb_hcd_reset_endpoint(struct usb_device *udev, * @num_streams: number of streams to allocate. * @mem_flags: flags hcd should use to allocate memory. * - * Sets up a group of bulk endpoints to have num_streams stream IDs available. + * Sets up a group of bulk endpoints to have @num_streams stream IDs available. * Drivers may queue multiple transfers to different stream IDs, which may * complete in a different order than they were queued. + * + * Return: On success, the number of allocated streams. On failure, a negative + * error code. */ int usb_alloc_streams(struct usb_interface *interface, struct usb_host_endpoint **eps, unsigned int num_eps, @@ -2201,6 +2212,8 @@ EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub); * khubd identifying and possibly configuring the device. * This is needed by OTG controller drivers, where it helps meet * HNP protocol timing requirements for starting a port reset. + * + * Return: 0 if successful. */ int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num) { @@ -2235,6 +2248,8 @@ EXPORT_SYMBOL_GPL(usb_bus_start_enum); * * If the controller isn't HALTed, calls the driver's irq handler. * Checks whether the controller is now dead. + * + * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise. */ irqreturn_t usb_hcd_irq (int irq, void *__hcd) { @@ -2320,7 +2335,8 @@ EXPORT_SYMBOL_GPL (usb_hc_died); * HC driver's private data. Initialize the generic members of the * hcd structure. * - * If memory is unavailable, returns NULL. + * Return: On success, a pointer to the created and initialized HCD structure. + * On failure (e.g. if memory is unavailable), %NULL. */ struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver, struct device *dev, const char *bus_name, @@ -2384,7 +2400,8 @@ EXPORT_SYMBOL_GPL(usb_create_shared_hcd); * HC driver's private data. Initialize the generic members of the * hcd structure. * - * If memory is unavailable, returns NULL. + * Return: On success, a pointer to the created and initialized HCD + * structure. On failure (e.g. if memory is unavailable), %NULL. */ struct usb_hcd *usb_create_hcd(const struct hc_driver *driver, struct device *dev, const char *bus_name) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 4191db3..b22cbf8 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -725,6 +725,8 @@ static void hub_tt_work(struct work_struct *work) * * call this function to control port's power via setting or * clearing the port's PORT_POWER feature. + * + * Return: 0 if successful. A negative error code otherwise. */ int usb_hub_set_port_power(struct usb_device *hdev, struct usb_hub *hub, int port1, bool set) @@ -753,6 +755,8 @@ int usb_hub_set_port_power(struct usb_device *hdev, struct usb_hub *hub, * * It may not be possible for that hub to handle additional full (or low) * speed transactions until that state is fully cleared out. + * + * Return: 0 if successful. A negative error code otherwise. */ int usb_hub_clear_tt_buffer(struct urb *urb) { @@ -955,6 +959,8 @@ static void hub_port_logical_disconnect(struct usb_hub *hub, int port1) * see that the device has been disconnected. When the device is * physically unplugged and something is plugged in, the events will * be received and processed normally. + * + * Return: 0 if successful. A negative error code otherwise. */ int usb_remove_device(struct usb_device *udev) { @@ -2107,6 +2113,8 @@ static inline void announce_device(struct usb_device *udev) { } * @udev: newly addressed device (in ADDRESS state) * * Finish enumeration for On-The-Go devices + * + * Return: 0 if successful. A negative error code otherwise. */ static int usb_enumerate_device_otg(struct usb_device *udev) { @@ -2189,6 +2197,8 @@ fail: * If the device is WUSB and not authorized, we don't attempt to read * the string descriptors, as they will be errored out by the device * until it has been authorized. + * + * Return: 0 if successful. A negative error code otherwise. */ static int usb_enumerate_device(struct usb_device *udev) { @@ -2269,13 +2279,14 @@ static void set_usb_port_removable(struct usb_device *udev) * udev has already been installed, but udev is not yet visible through * sysfs or other filesystem code. * - * It will return if the device is configured properly or not. Zero if - * the interface was registered with the driver core; else a negative - * errno value. - * * This call is synchronous, and may not be used in an interrupt context. * * Only the hub driver or root-hub registrar should ever call this. + * + * Return: Whether the device is configured properly or not. Zero if the + * interface was registered with the driver core; else a negative errno + * value. + * */ int usb_new_device(struct usb_device *udev) { @@ -2383,6 +2394,8 @@ fail: * * We share a lock (that we have) with device_del(), so we need to * defer its call. + * + * Return: 0. */ int usb_deauthorize_device(struct usb_device *usb_dev) { @@ -5002,10 +5015,11 @@ static int descriptors_changed(struct usb_device *udev, * re-connected. All drivers will be unbound, and the device will be * re-enumerated and probed all over again. * - * Returns 0 if the reset succeeded, -ENODEV if the device has been + * Return: 0 if the reset succeeded, -ENODEV if the device has been * flagged for logical disconnection, or some other negative error code * if the reset wasn't even attempted. * + * Note: * The caller must own the device lock. For example, it's safe to use * this from a driver probe() routine after downloading new firmware. * For calls that might not occur during probe(), drivers should lock @@ -5161,8 +5175,9 @@ re_enumerate: * method), performs the port reset, and then lets the drivers know that * the reset is over (using their post_reset method). * - * Return value is the same as for usb_reset_and_verify_device(). + * Return: The same as for usb_reset_and_verify_device(). * + * Note: * The caller must own the device lock. For example, it's safe to use * this from a driver probe() routine after downloading new firmware. * For calls that might not occur during probe(), drivers should lock @@ -5300,7 +5315,7 @@ EXPORT_SYMBOL_GPL(usb_queue_reset_device); * USB drivers call this function to get hub's child device * pointer. * - * Return NULL if input param is invalid and + * Return: %NULL if input param is invalid and * child's usb_device pointer if non-NULL. */ struct usb_device *usb_hub_find_child(struct usb_device *hdev, @@ -5334,8 +5349,8 @@ void usb_set_hub_port_connect_type(struct usb_device *hdev, int port1, * @hdev: USB device belonging to the usb hub * @port1: port num of the port * - * Return connect type of the port and if input params are - * invalid, return USB_PORT_CONNECT_TYPE_UNKNOWN. + * Return: The connect type of the port if successful. Or + * USB_PORT_CONNECT_TYPE_UNKNOWN if input params are invalid. */ enum usb_port_connect_type usb_get_hub_port_connect_type(struct usb_device *hdev, int port1) @@ -5395,8 +5410,8 @@ void usb_hub_adjust_deviceremovable(struct usb_device *hdev, * @hdev: USB device belonging to the usb hub * @port1: port num of the port * - * Return port's acpi handle if successful, NULL if params are - * invaild. + * Return: Port's acpi handle if successful, %NULL if params are + * invalid. */ acpi_handle usb_get_hub_port_acpi_handle(struct usb_device *hdev, int port1) diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index e7ee1e4..d2bc45b 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -119,15 +119,15 @@ static int usb_internal_control_msg(struct usb_device *usb_dev, * This function sends a simple control message to a specified endpoint and * waits for the message to complete, or timeout. * - * If successful, it returns the number of bytes transferred, otherwise a - * negative error number. - * * Don't use this function from within an interrupt context, like a bottom half * handler. If you need an asynchronous message, or need to send a message * from within interrupt context, use usb_submit_urb(). * If a thread in your driver uses this call, make sure your disconnect() * method can wait for it to complete. Since you don't have a handle on the * URB used, you can't cancel the request. + * + * Return: If successful, the number of bytes transferred. Otherwise, a negative + * error number. */ int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request, __u8 requesttype, __u16 value, __u16 index, void *data, @@ -170,15 +170,16 @@ EXPORT_SYMBOL_GPL(usb_control_msg); * This function sends a simple interrupt message to a specified endpoint and * waits for the message to complete, or timeout. * - * If successful, it returns 0, otherwise a negative error number. The number - * of actual bytes transferred will be stored in the actual_length paramater. - * * Don't use this function from within an interrupt context, like a bottom half * handler. If you need an asynchronous message, or need to send a message * from within interrupt context, use usb_submit_urb() If a thread in your * driver uses this call, make sure your disconnect() method can wait for it to * complete. Since you don't have a handle on the URB used, you can't cancel * the request. + * + * Return: + * If successful, 0. Otherwise a negative error number. The number of actual + * bytes transferred will be stored in the @actual_length paramater. */ int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe, void *data, int len, int *actual_length, int timeout) @@ -203,9 +204,6 @@ EXPORT_SYMBOL_GPL(usb_interrupt_msg); * This function sends a simple bulk message to a specified endpoint * and waits for the message to complete, or timeout. * - * If successful, it returns 0, otherwise a negative error number. The number - * of actual bytes transferred will be stored in the actual_length paramater. - * * Don't use this function from within an interrupt context, like a bottom half * handler. If you need an asynchronous message, or need to send a message * from within interrupt context, use usb_submit_urb() If a thread in your @@ -217,6 +215,11 @@ EXPORT_SYMBOL_GPL(usb_interrupt_msg); * users are forced to abuse this routine by using it to submit URBs for * interrupt endpoints. We will take the liberty of creating an interrupt URB * (with the default interval) if the target is an interrupt endpoint. + * + * Return: + * If successful, 0. Otherwise a negative error number. The number of actual + * bytes transferred will be stored in the @actual_length paramater. + * */ int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe, void *data, int len, int *actual_length, int timeout) @@ -341,9 +344,9 @@ static void sg_complete(struct urb *urb) * send every byte identified in the list. * @mem_flags: SLAB_* flags affecting memory allocations in this call * - * Returns zero for success, else a negative errno value. This initializes a - * scatter/gather request, allocating resources such as I/O mappings and urb - * memory (except maybe memory used by USB controller drivers). + * This initializes a scatter/gather request, allocating resources such as + * I/O mappings and urb memory (except maybe memory used by USB controller + * drivers). * * The request must be issued using usb_sg_wait(), which waits for the I/O to * complete (or to be canceled) and then cleans up all resources allocated by @@ -351,6 +354,8 @@ static void sg_complete(struct urb *urb) * * The request may be canceled with usb_sg_cancel(), either before or after * usb_sg_wait() is called. + * + * Return: Zero for success, else a negative errno value. */ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, unsigned pipe, unsigned period, struct scatterlist *sg, @@ -623,7 +628,7 @@ EXPORT_SYMBOL_GPL(usb_sg_cancel); * * This call is synchronous, and may not be used in an interrupt context. * - * Returns the number of bytes received on success, or else the status code + * Return: The number of bytes received on success, or else the status code * returned by the underlying usb_control_msg() call. */ int usb_get_descriptor(struct usb_device *dev, unsigned char type, @@ -671,7 +676,7 @@ EXPORT_SYMBOL_GPL(usb_get_descriptor); * * This call is synchronous, and may not be used in an interrupt context. * - * Returns the number of bytes received on success, or else the status code + * Return: The number of bytes received on success, or else the status code * returned by the underlying usb_control_msg() call. */ static int usb_get_string(struct usb_device *dev, unsigned short langid, @@ -805,7 +810,7 @@ static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf) * * This call is synchronous, and may not be used in an interrupt context. * - * Returns length of the string (>= 0) or usb_control_msg status (< 0). + * Return: length of the string (>= 0) or usb_control_msg status (< 0). */ int usb_string(struct usb_device *dev, int index, char *buf, size_t size) { @@ -853,8 +858,8 @@ EXPORT_SYMBOL_GPL(usb_string); * @udev: the device whose string descriptor is being read * @index: the descriptor index * - * Returns a pointer to a kmalloc'ed buffer containing the descriptor string, - * or NULL if the index is 0 or the string could not be read. + * Return: A pointer to a kmalloc'ed buffer containing the descriptor string, + * or %NULL if the index is 0 or the string could not be read. */ char *usb_cache_string(struct usb_device *udev, int index) { @@ -934,7 +939,7 @@ int usb_get_device_descriptor(struct usb_device *dev, unsigned int size) * * This call is synchronous, and may not be used in an interrupt context. * - * Returns the number of bytes received on success, or else the status code + * Return: The number of bytes received on success, or else the status code * returned by the underlying usb_control_msg() call. */ int usb_get_status(struct usb_device *dev, int type, int target, void *data) @@ -975,7 +980,7 @@ EXPORT_SYMBOL_GPL(usb_get_status); * * This call is synchronous, and may not be used in an interrupt context. * - * Returns zero on success, or else the status code returned by the + * Return: Zero on success, or else the status code returned by the * underlying usb_control_msg() call. */ int usb_clear_halt(struct usb_device *dev, int pipe) @@ -1272,7 +1277,7 @@ void usb_enable_interface(struct usb_device *dev, * endpoints in that interface; all such urbs must first be completed * (perhaps forced by unlinking). * - * Returns zero on success, or else the status code returned by the + * Return: Zero on success, or else the status code returned by the * underlying usb_control_msg() call. */ int usb_set_interface(struct usb_device *dev, int interface, int alternate) @@ -1426,7 +1431,7 @@ EXPORT_SYMBOL_GPL(usb_set_interface); * * The caller must own the device lock. * - * Returns zero on success, else a negative error code. + * Return: Zero on success, else a negative error code. */ int usb_reset_configuration(struct usb_device *dev) { @@ -1968,7 +1973,7 @@ static void cancel_async_set_config(struct usb_device *udev) * routine gets around the normal restrictions by using a work thread to * submit the change-config request. * - * Returns 0 if the request was successfully queued, error code otherwise. + * Return: 0 if the request was successfully queued, error code otherwise. * The caller has no way to know whether the queued request will eventually * succeed. */ diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 16927fa..e88a99f 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -54,12 +54,12 @@ EXPORT_SYMBOL_GPL(usb_init_urb); * Creates an urb for the USB driver to use, initializes a few internal * structures, incrementes the usage counter, and returns a pointer to it. * - * If no memory is available, NULL is returned. - * * If the driver want to use this urb for interrupt, control, or bulk * endpoints, pass '0' as the number of iso packets. * * The driver must call usb_free_urb() when it is finished with the urb. + * + * Return: A pointer to the new urb, or %NULL if no memory is available. */ struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags) { @@ -102,7 +102,7 @@ EXPORT_SYMBOL_GPL(usb_free_urb); * host controller driver. This allows proper reference counting to happen * for urbs. * - * A pointer to the urb with the incremented reference counter is returned. + * Return: A pointer to the urb with the incremented reference counter. */ struct urb *usb_get_urb(struct urb *urb) { @@ -199,13 +199,12 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); * the particular kind of transfer, although they will not initialize * any transfer flags. * - * Successful submissions return 0; otherwise this routine returns a - * negative error number. If the submission is successful, the complete() - * callback from the URB will be called exactly once, when the USB core and - * Host Controller Driver (HCD) are finished with the URB. When the completion - * function is called, control of the URB is returned to the device - * driver which issued the request. The completion handler may then - * immediately free or reuse that URB. + * If the submission is successful, the complete() callback from the URB + * will be called exactly once, when the USB core and Host Controller Driver + * (HCD) are finished with the URB. When the completion function is called, + * control of the URB is returned to the device driver which issued the + * request. The completion handler may then immediately free or reuse that + * URB. * * With few exceptions, USB device drivers should never access URB fields * provided by usbcore or the HCD until its complete() is called. @@ -240,6 +239,9 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); * that are standardized in the USB 2.0 specification. For bulk * endpoints, a synchronous usb_bulk_msg() call is available. * + * Return: + * 0 on successful submissions. A negative error number otherwise. + * * Request Queuing: * * URBs may be submitted to endpoints before previous ones complete, to @@ -564,6 +566,9 @@ EXPORT_SYMBOL_GPL(usb_submit_urb); * particular, when a driver calls this routine, it must insure that the * completion handler cannot deallocate the URB. * + * Return: -EINPROGRESS on success. See description for other values on + * failure. + * * Unlinking and Endpoint Queues: * * [The behaviors and guarantees described below do not apply to virtual @@ -838,6 +843,8 @@ EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs); * * Call this is you want to be sure all an anchor's * URBs have finished + * + * Return: Non-zero if the anchor became unused. Zero on timeout. */ int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, unsigned int timeout) @@ -851,8 +858,11 @@ EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); * usb_get_from_anchor - get an anchor's oldest urb * @anchor: the anchor whose urb you want * - * this will take the oldest urb from an anchor, + * This will take the oldest urb from an anchor, * unanchor and return it + * + * Return: The oldest urb from @anchor, or %NULL if @anchor has no + * urbs associated with it. */ struct urb *usb_get_from_anchor(struct usb_anchor *anchor) { @@ -901,7 +911,7 @@ EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs); * usb_anchor_empty - is an anchor empty * @anchor: the anchor you want to query * - * returns 1 if the anchor has no urbs associated with it + * Return: 1 if the anchor has no urbs associated with it. */ int usb_anchor_empty(struct usb_anchor *anchor) { diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 7dad603..0a6ee2e 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -68,6 +68,8 @@ MODULE_PARM_DESC(autosuspend, "default autosuspend delay"); * @alt_num: alternate interface setting number to search for. * * Search the configuration's interface cache for the given alt setting. + * + * Return: The alternate setting, if found. %NULL otherwise. */ struct usb_host_interface *usb_find_alt_setting( struct usb_host_config *config, @@ -103,8 +105,7 @@ EXPORT_SYMBOL_GPL(usb_find_alt_setting); * @ifnum: the desired interface * * This walks the device descriptor for the currently active configuration - * and returns a pointer to the interface with that particular interface - * number, or null. + * to find the interface object with the particular interface number. * * Note that configuration descriptors are not required to assign interface * numbers sequentially, so that it would be incorrect to assume that @@ -115,6 +116,9 @@ EXPORT_SYMBOL_GPL(usb_find_alt_setting); * * Don't call this function unless you are bound to one of the interfaces * on this device or you have locked the device! + * + * Return: A pointer to the interface that has @ifnum as interface number, + * if found. %NULL otherwise. */ struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev, unsigned ifnum) @@ -139,8 +143,7 @@ EXPORT_SYMBOL_GPL(usb_ifnum_to_if); * @altnum: the desired alternate setting number * * This searches the altsetting array of the specified interface for - * an entry with the correct bAlternateSetting value and returns a pointer - * to that entry, or null. + * an entry with the correct bAlternateSetting value. * * Note that altsettings need not be stored sequentially by number, so * it would be incorrect to assume that the first altsetting entry in @@ -149,6 +152,9 @@ EXPORT_SYMBOL_GPL(usb_ifnum_to_if); * * Don't call this function unless you are bound to the intf interface * or you have locked the device! + * + * Return: A pointer to the entry of the altsetting array of @intf that + * has @altnum as the alternate setting number. %NULL if not found. */ struct usb_host_interface *usb_altnum_to_altsetting( const struct usb_interface *intf, @@ -191,6 +197,8 @@ static int __find_interface(struct device *dev, void *data) * This walks the bus device list and returns a pointer to the interface * with the matching minor and driver. Note, this only works for devices * that share the USB major number. + * + * Return: A pointer to the interface with the matching major and @minor. */ struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) { @@ -390,6 +398,9 @@ static unsigned usb_bus_is_wusb(struct usb_bus *bus) * controllers) should ever call this. * * This call may not be used in a non-sleeping context. + * + * Return: On success, a pointer to the allocated usb device. %NULL on + * failure. */ struct usb_device *usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1) @@ -501,7 +512,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent, * their probe() methods, when they bind to an interface, and release * them by calling usb_put_dev(), in their disconnect() methods. * - * A pointer to the device with the incremented reference counter is returned. + * Return: A pointer to the device with the incremented reference counter. */ struct usb_device *usb_get_dev(struct usb_device *dev) { @@ -535,8 +546,7 @@ EXPORT_SYMBOL_GPL(usb_put_dev); * their probe() methods, when they bind to an interface, and release * them by calling usb_put_intf(), in their disconnect() methods. * - * A pointer to the interface with the incremented reference counter is - * returned. + * Return: A pointer to the interface with the incremented reference counter. */ struct usb_interface *usb_get_intf(struct usb_interface *intf) { @@ -589,7 +599,7 @@ EXPORT_SYMBOL_GPL(usb_put_intf); * disconnect; in some drivers (such as usb-storage) the disconnect() * or suspend() method will block waiting for a device reset to complete. * - * Returns a negative error code for failure, otherwise 0. + * Return: A negative error code for failure, otherwise 0. */ int usb_lock_device_for_reset(struct usb_device *udev, const struct usb_interface *iface) @@ -628,14 +638,15 @@ EXPORT_SYMBOL_GPL(usb_lock_device_for_reset); * usb_get_current_frame_number - return current bus frame number * @dev: the device whose bus is being queried * - * Returns the current frame number for the USB host controller - * used with the given USB device. This can be used when scheduling + * Return: The current frame number for the USB host controller used + * with the given USB device. This can be used when scheduling * isochronous requests. * - * Note that different kinds of host controller have different - * "scheduling horizons". While one type might support scheduling only - * 32 frames into the future, others could support scheduling up to - * 1024 frames into the future. + * Note: Different kinds of host controller have different "scheduling + * horizons". While one type might support scheduling only 32 frames + * into the future, others could support scheduling up to 1024 frames + * into the future. + * */ int usb_get_current_frame_number(struct usb_device *dev) { @@ -685,11 +696,12 @@ EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor); * @mem_flags: affect whether allocation may block * @dma: used to return DMA address of buffer * - * Return value is either null (indicating no buffer could be allocated), or - * the cpu-space pointer to a buffer that may be used to perform DMA to the + * Return: Either null (indicating no buffer could be allocated), or the + * cpu-space pointer to a buffer that may be used to perform DMA to the * specified device. Such cpu-space buffers are returned along with the DMA * address (through the pointer provided). * + * Note: * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU * hardware during URB completion/resubmit. The implementation varies between @@ -735,17 +747,18 @@ EXPORT_SYMBOL_GPL(usb_free_coherent); * usb_buffer_map - create DMA mapping(s) for an urb * @urb: urb whose transfer_buffer/setup_packet will be mapped * - * Return value is either null (indicating no buffer could be mapped), or - * the parameter. URB_NO_TRANSFER_DMA_MAP is - * added to urb->transfer_flags if the operation succeeds. If the device - * is connected to this system through a non-DMA controller, this operation - * always succeeds. + * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation + * succeeds. If the device is connected to this system through a non-DMA + * controller, this operation always succeeds. * * This call would normally be used for an urb which is reused, perhaps * as the target of a large periodic transfer, with usb_buffer_dmasync() * calls to synchronize memory and dma state. * * Reverse the effect of this call with usb_buffer_unmap(). + * + * Return: Either %NULL (indicating no buffer could be mapped), or @urb. + * */ #if 0 struct urb *usb_buffer_map(struct urb *urb) @@ -850,9 +863,10 @@ EXPORT_SYMBOL_GPL(usb_buffer_unmap); * @sg: the scatterlist to map * @nents: the number of entries in the scatterlist * - * Return value is either < 0 (indicating no buffers could be mapped), or - * the number of DMA mapping array entries in the scatterlist. + * Return: Either < 0 (indicating no buffers could be mapped), or the + * number of DMA mapping array entries in the scatterlist. * + * Note: * The caller is responsible for placing the resulting DMA addresses from * the scatterlist into URB transfer buffer pointers, and for setting the * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs. diff --git a/include/linux/usb.h b/include/linux/usb.h index a232b7e..9fd0111 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -719,7 +719,10 @@ extern int usb_driver_claim_interface(struct usb_driver *driver, * usb_interface_claimed - returns true iff an interface is claimed * @iface: the interface being checked * - * Returns true (nonzero) iff the interface is claimed, else false (zero). + * Return: %true (nonzero) iff the interface is claimed, else %false + * (zero). + * + * Note: * Callers must own the driver model's usb bus readlock. So driver * probe() entries don't need extra locking, but other call contexts * may need to explicitly claim that lock. @@ -756,8 +759,9 @@ extern struct usb_host_interface *usb_find_alt_setting( * @buf: where to put the string * @size: how big is "buf"? * - * Returns length of the string (> 0) or negative if size was too small. + * Return: Length of the string (> 0) or negative if size was too small. * + * Note: * This identifier is intended to be "stable", reflecting physical paths in * hardware such as physical bus addresses for host controllers or ports on * USB hubs. That makes it stay the same until systems are physically @@ -1581,7 +1585,7 @@ extern int usb_anchor_empty(struct usb_anchor *anchor); * usb_urb_dir_in - check if an URB describes an IN transfer * @urb: URB to be checked * - * Returns 1 if @urb describes an IN transfer (device-to-host), + * Return: 1 if @urb describes an IN transfer (device-to-host), * otherwise 0. */ static inline int usb_urb_dir_in(struct urb *urb) @@ -1593,7 +1597,7 @@ static inline int usb_urb_dir_in(struct urb *urb) * usb_urb_dir_out - check if an URB describes an OUT transfer * @urb: URB to be checked * - * Returns 1 if @urb describes an OUT transfer (host-to-device), + * Return: 1 if @urb describes an OUT transfer (host-to-device), * otherwise 0. */ static inline int usb_urb_dir_out(struct urb *urb) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html