Hi Tobias, 於 四，2011-06-16 於 13:38 +0200，Tobias Klauser 提到： > Use a local pointer to reference the urb instead of dereferencing the > priv->urb member all over the function. >
What's the benefit for use local pointer to instead of priv->urb? Does it for coding style? Thank's Joey Lee > Signed-off-by: Tobias Klauser <[email protected]> > --- > drivers/staging/usbip/stub_rx.c | 44 +++++++++++++++++++------------------- > 1 files changed, 22 insertions(+), 22 deletions(-) > > diff --git a/drivers/staging/usbip/stub_rx.c b/drivers/staging/usbip/stub_rx.c > index 538fb9e..8d40e5e 100644 > --- a/drivers/staging/usbip/stub_rx.c > +++ b/drivers/staging/usbip/stub_rx.c > @@ -469,6 +469,7 @@ static void stub_recv_cmd_submit(struct stub_device *sdev, > { > int ret; > struct stub_priv *priv; > + struct urb *urb; > struct usbip_device *ud = &sdev->ud; > struct usb_device *udev = sdev->udev; > int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction); > @@ -479,12 +480,14 @@ static void stub_recv_cmd_submit(struct stub_device > *sdev, > > /* setup a urb */ > if (usb_pipeisoc(pipe)) > - priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets, > - GFP_KERNEL); > + urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets, > + GFP_KERNEL); > else > - priv->urb = usb_alloc_urb(0, GFP_KERNEL); > + urb = usb_alloc_urb(0, GFP_KERNEL); > > - if (!priv->urb) { > + priv->urb = urb; > + > + if (!urb) { > dev_err(&sdev->interface->dev, "malloc urb\n"); > usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC); > return; > @@ -492,10 +495,10 @@ static void stub_recv_cmd_submit(struct stub_device > *sdev, > > /* set priv->urb->transfer_buffer */ > if (pdu->u.cmd_submit.transfer_buffer_length > 0) { > - priv->urb->transfer_buffer = > + urb->transfer_buffer = > kzalloc(pdu->u.cmd_submit.transfer_buffer_length, > GFP_KERNEL); > - if (!priv->urb->transfer_buffer) { > + if (!urb->transfer_buffer) { > dev_err(&sdev->interface->dev, "malloc x_buff\n"); > usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC); > return; > @@ -503,43 +506,40 @@ static void stub_recv_cmd_submit(struct stub_device > *sdev, > } > > /* set priv->urb->setup_packet */ > - priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8, > - GFP_KERNEL); > - if (!priv->urb->setup_packet) { > + urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8, GFP_KERNEL); > + if (!urb->setup_packet) { > dev_err(&sdev->interface->dev, "allocate setup_packet\n"); > usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC); > return; > } > > /* set other members from the base header of pdu */ > - priv->urb->context = (void *) priv; > - priv->urb->dev = udev; > - priv->urb->pipe = pipe; > - priv->urb->complete = stub_complete; > - > - usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0); > + urb->context = (void *) priv; > + urb->dev = udev; > + urb->pipe = pipe; > + urb->complete = stub_complete; > > + usbip_pack_pdu(pdu, urb, USBIP_CMD_SUBMIT, 0); > > - if (usbip_recv_xbuff(ud, priv->urb) < 0) > + if (usbip_recv_xbuff(ud, urb) < 0) > return; > > - if (usbip_recv_iso(ud, priv->urb) < 0) > + if (usbip_recv_iso(ud, urb) < 0) > return; > > /* no need to submit an intercepted request, but harmless? */ > - tweak_special_requests(priv->urb); > + tweak_special_requests(urb); > > - masking_bogus_flags(priv->urb); > + masking_bogus_flags(urb); > /* urb is now ready to submit */ > - ret = usb_submit_urb(priv->urb, GFP_KERNEL); > - > + ret = usb_submit_urb(urb, GFP_KERNEL); > if (ret == 0) > usbip_dbg_stub_rx("submit urb ok, seqnum %u\n", > pdu->base.seqnum); > else { > dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret); > usbip_dump_header(pdu); > - usbip_dump_urb(priv->urb); > + usbip_dump_urb(urb); > > /* > * Pessimistic. _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
