diff options
Diffstat (limited to 'include/linux/usb.h')
| -rw-r--r-- | include/linux/usb.h | 45 |
1 files changed, 33 insertions, 12 deletions
diff --git a/include/linux/usb.h b/include/linux/usb.h index 7d5325d47c45..9642ee02d713 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -267,16 +267,15 @@ static inline void *usb_get_intfdata(struct usb_interface *intf) } /** - * usb_set_intfdata() - associate driver-specific data with the interface - * @intf: the usb interface - * @data: pointer to the device priv structure or %NULL + * usb_set_intfdata() - associate driver-specific data with an interface + * @intf: USB interface + * @data: driver data * - * Drivers should use this function in their probe() to associate their - * driver-specific data with the usb interface. + * Drivers can use this function in their probe() callbacks to associate + * driver-specific data with an interface. * - * When disconnecting, the core will take care of setting @intf back to %NULL, - * so no actions are needed on the driver side. The interface should not be set - * to %NULL before all actions completed (e.g. no outsanding URB remaining). + * Note that there is generally no need to clear the driver-data pointer even + * if some drivers do so for historical or implementation-specific reasons. */ static inline void usb_set_intfdata(struct usb_interface *intf, void *data) { @@ -774,11 +773,14 @@ extern struct device *usb_intf_get_dma_device(struct usb_interface *intf); extern int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable); extern bool usb_acpi_power_manageable(struct usb_device *hdev, int index); +extern int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index); #else static inline int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable) { return 0; } static inline bool usb_acpi_power_manageable(struct usb_device *hdev, int index) { return true; } +static inline int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index) + { return 0; } #endif /* USB autosuspend and autoresume */ @@ -1626,14 +1628,25 @@ struct urb { * @urb: pointer to the urb to initialize. * @dev: pointer to the struct usb_device for this urb. * @pipe: the endpoint pipe - * @setup_packet: pointer to the setup_packet buffer - * @transfer_buffer: pointer to the transfer buffer + * @setup_packet: pointer to the setup_packet buffer. The buffer must be + * suitable for DMA. + * @transfer_buffer: pointer to the transfer buffer. The buffer must be + * suitable for DMA. * @buffer_length: length of the transfer buffer * @complete_fn: pointer to the usb_complete_t function * @context: what to set the urb context to. * * Initializes a control urb with the proper information needed to submit * it to a device. + * + * The transfer buffer and the setup_packet buffer will most likely be filled + * or read via DMA. The simplest way to get a buffer that can be DMAed to is + * allocating it via kmalloc() or equivalent, even for very small buffers. + * If the buffers are embedded in a bigger structure, there is a risk that + * the buffer itself, the previous fields and/or the next fields are corrupted + * due to cache incoherencies; or slowed down if they are evicted from the + * cache. For more information, check &struct urb. + * */ static inline void usb_fill_control_urb(struct urb *urb, struct usb_device *dev, @@ -1658,13 +1671,17 @@ static inline void usb_fill_control_urb(struct urb *urb, * @urb: pointer to the urb to initialize. * @dev: pointer to the struct usb_device for this urb. * @pipe: the endpoint pipe - * @transfer_buffer: pointer to the transfer buffer + * @transfer_buffer: pointer to the transfer buffer. The buffer must be + * suitable for DMA. * @buffer_length: length of the transfer buffer * @complete_fn: pointer to the usb_complete_t function * @context: what to set the urb context to. * * Initializes a bulk urb with the proper information needed to submit it * to a device. + * + * Refer to usb_fill_control_urb() for a description of the requirements for + * transfer_buffer. */ static inline void usb_fill_bulk_urb(struct urb *urb, struct usb_device *dev, @@ -1687,7 +1704,8 @@ static inline void usb_fill_bulk_urb(struct urb *urb, * @urb: pointer to the urb to initialize. * @dev: pointer to the struct usb_device for this urb. * @pipe: the endpoint pipe - * @transfer_buffer: pointer to the transfer buffer + * @transfer_buffer: pointer to the transfer buffer. The buffer must be + * suitable for DMA. * @buffer_length: length of the transfer buffer * @complete_fn: pointer to the usb_complete_t function * @context: what to set the urb context to. @@ -1697,6 +1715,9 @@ static inline void usb_fill_bulk_urb(struct urb *urb, * Initializes a interrupt urb with the proper information needed to submit * it to a device. * + * Refer to usb_fill_control_urb() for a description of the requirements for + * transfer_buffer. + * * Note that High Speed and SuperSpeed(+) interrupt endpoints use a logarithmic * encoding of the endpoint interval, and express polling intervals in * microframes (eight per millisecond) rather than in frames (one per |