Re: [PATCHv3] drivers/net/usb: Add new driver ipheth

From: "L. Alberto GimÃnez"
Date: Fri Apr 02 2010 - 13:54:16 EST


On 04/02/2010 07:21 PM, Ben Hutchings wrote:
> On Fri, 2010-04-02 at 19:15 +0200, "L. Alberto GimÃnez" wrote:
>> On 04/01/2010 01:18 AM, Ben Hutchings wrote:
>>> On Wed, 2010-03-31 at 21:42 +0200, L. Alberto GimÃnez wrote:
>>> [...]
>>>> --- /dev/null
>>>> +++ b/drivers/net/usb/ipheth.c
>>> [...]
>>>> + usb_fill_bulk_urb(dev->tx_urb, udev,
>>>> + usb_sndbulkpipe(udev, dev->bulk_out),
>>>> + dev->tx_buf, IPHETH_BUF_SIZE,
>>>> + ipheth_sndbulk_callback,
>>>> + dev);
>>>> + dev->tx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
>>>> +
>>>> + retval = usb_submit_urb(dev->tx_urb, GFP_ATOMIC);
>>>> + if (retval) {
>>>> + err("%s: usb_submit_urb: %d", __func__, retval);
>>>> + dev->stats.tx_errors++;
>>>> + dev_kfree_skb_irq(skb);
>>>> + } else {
>>>> + net->trans_start = jiffies;
>>> No longer needed.
>> What is not longer needed? The assignment, the whole "else" branch? If
>> the assignment is what is not needed, can I just remove that line, right?
>
> The assignment is not needed.

Hi,

I've been looking into this and it seems that the net_device.trans_start
field is now deprecated in favor of net_device.rx_queue.trans_start
-rx_queue is a struct netdev_queue- (file include/linux/netdevice.h), as
states the comment:

512 /*
513 * please use this field instead of dev->trans_start
514 */
515 unsigned long trans_start;

Reading LDD3 book, it says that the driver is reponsible for updating
trans_start (as well as trans_rx, but we're not talking about that one).

So, I guess that the LDD book is outdated (again ;) ), but what I don't
understand at all is wether the driver should keep updating the right
field (dev->rx_queue.trans_start) or if the fact that it's inside a
"queue" implies that the code that is responsible for that queue would
update the trans_start field by itself?

Thanks in advance.

Best regards,
--
L. Alberto GimÃnez
JabberID agimenez@xxxxxxxxxxxxxxxxxx
GnuPG key ID 0x3BAABDE1
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