USB_BULK_MSG

Section: USB Core APIs (9)
Updated: February 2011
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NAME

usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion

SYNOPSIS

int usb_bulk_msg(struct usb_device * usb_dev, unsigned int pipe, void * data, int len, int * actual_length, int timeout);

ARGUMENTS

usb_dev

: pointer to the usb device to send the message to

pipe

: endpoint lqpiperq to send the message to

data

: pointer to the data to send

len

: length in bytes of the data to send

actual_length

: pointer to a location to put the actual length transferred in bytes

timeout

: time in msecs to wait for the message to complete before timing out (if 0 the wait is forever)

CONTEXT

!in_interrupt ()

DESCRIPTION

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 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.