On Wed, 2010-09-01 at 09:43 +0800, Liang Li wrote:
> It's common sense that when we should do change to driver ring
> desc/buffer etc only after 'stop/shutdown' the device. When we
> do change while devices/driver is running, kernel oops occur:
[...]
> - ug_info->bdRingLenRx[queue] = ring->rx_pending;
> - ug_info->bdRingLenTx[queue] = ring->tx_pending;
> -
> if (netif_running(netdev)) {
> - /* FIXME: restart automatically */
> - printk(KERN_INFO
> - "Please re-open the interface.\n");
> + u16 rx_t;
> + u16 tx_t;
> + printk(KERN_INFO "Stopping interface %s.\n", netdev->name);
> + ucc_geth_close(netdev);
> +
> + rx_t = ug_info->bdRingLenRx[queue];
> + tx_t = ug_info->bdRingLenTx[queue];
> +
> + ug_info->bdRingLenRx[queue] = ring->rx_pending;
> + ug_info->bdRingLenTx[queue] = ring->tx_pending;
> +
> + printk(KERN_INFO "Reactivating interface %s.\n", netdev->name);
> + ret = ucc_geth_open(netdev);
> + if (ret) {
> + printk(KERN_WARNING "uec_set_ringparam: set ring param
> for running"
> + " interface %s failed. Please try to
> make the interface "
> + " down, then try again.\n",
> netdev->name);
> + ug_info->bdRingLenRx[queue] = rx_t;
> + ug_info->bdRingLenTx[queue] = tx_t;
> + }
[...]
Bringing the interface down will call ucc_geth_close(), which will try
to free resources that have not been allocated!
If you cannot roll back a failed change then at least use dev_close()
and dev_open() rather than calling ucc_geth_{close,open}() directly, so
that the interface state is updated correctly. Or just refuse to make
the change if the interface is up.
Ben.
--
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
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