diff options
Diffstat (limited to '')
| -rw-r--r-- | Documentation/driver-api/usb/writing_usb_driver.rst | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/Documentation/driver-api/usb/writing_usb_driver.rst b/Documentation/driver-api/usb/writing_usb_driver.rst index b43e1ce49f0e..95c4f5d14052 100644 --- a/Documentation/driver-api/usb/writing_usb_driver.rst +++ b/Documentation/driver-api/usb/writing_usb_driver.rst @@ -94,8 +94,8 @@ usually in the driver's init function, as shown here:: /* register this driver with the USB subsystem */ result = usb_register(&skel_driver); if (result < 0) { - err("usb_register failed for the "__FILE__ "driver." - "Error number %d", result); + pr_err("usb_register failed for the %s driver. Error number %d\n", + skel_driver.name, result); return -1; } @@ -170,8 +170,8 @@ structure. This is done so that future calls to file operations will enable the driver to determine which device the user is addressing. All of this is done with the following code:: - /* increment our usage count for the module */ - ++skel->open_count; + /* increment our usage count for the device */ + kref_get(&dev->kref); /* save our object in the file's private structure */ file->private_data = dev; @@ -188,24 +188,26 @@ space, points the urb to the data and submits the urb to the USB subsystem. This can be seen in the following code:: /* we can only write as much as 1 urb will hold */ - bytes_written = (count > skel->bulk_out_size) ? skel->bulk_out_size : count; + size_t writesize = min_t(size_t, count, MAX_TRANSFER); /* copy the data from user space into our urb */ - copy_from_user(skel->write_urb->transfer_buffer, buffer, bytes_written); + copy_from_user(buf, user_buffer, writesize); /* set up our urb */ - usb_fill_bulk_urb(skel->write_urb, - skel->dev, - usb_sndbulkpipe(skel->dev, skel->bulk_out_endpointAddr), - skel->write_urb->transfer_buffer, - bytes_written, + usb_fill_bulk_urb(urb, + dev->udev, + usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), + buf, + writesize, skel_write_bulk_callback, - skel); + dev); /* send the data out the bulk port */ - result = usb_submit_urb(skel->write_urb); - if (result) { - err("Failed submitting write urb, error %d", result); + retval = usb_submit_urb(urb, GFP_KERNEL); + if (retval) { + dev_err(&dev->interface->dev, + "%s - failed submitting write urb, error %d\n", + __func__, retval); } |