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    SubjectRe: [PATCH] drivers/net/usb/asix: resync from vendor's copy
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    On Wed, 2011-11-09 at 12:40 -0500, Mark Lord wrote:
    > On 11-11-09 12:31 PM, Ben Hutchings wrote:
    > > On Wed, 2011-11-09 at 12:20 -0500, Mark Lord wrote:
    > >> On 11-11-09 11:57 AM, Mark Lord wrote:
    > >>> On 11-11-09 11:47 AM, Mark Lord wrote:
    > >>> ..
    > >>>> Note: I'm looking at smsc95xx.c and smsc75xx.c for examples,
    > >>>> and they both have the same problem I'll have here:
    > >>>>
    > >>>> How to update the csum settings atomically.
    > >>>> A spinlock is no good, because config register access is over USB.
    > >>>
    > >>> Nevermind.. a slight change in the logic and all is well again.
    > >> ..
    > >>
    > >> Or even simpler (below). I don't think this method requires any
    > >> extra locking, but I'm still open to persuasion. :)
    > >
    > > Looks reasonable, but...
    > >
    > >> static int ax88772b_set_features(struct net_device *netdev, u32 features)
    > >> {
    > >> struct usbnet *dev = netdev_priv(netdev);
    > >> struct ax88772b_data *priv = (struct ax88772b_data *)dev->driver_priv;
    > >> u16 tx_csum = 0, rx_csum = 0;
    > >>
    > >> priv->features = features & (NETIF_F_HW_CSUM | NETIF_F_RXCSUM);
    > >
    > > ...why do you need priv->features at all?
    >
    >
    > There's code elsewhere that takes action under some conditions
    > based on the current setting of the NETIF_F_RXCSUM flag.
    >
    > I don't claim to fully understand what's going on,
    > but it doesn't care much about races on set/clear of the flag.

    And it can use dev->features.

    Ben.

    --
    Ben Hutchings, Staff Engineer, Solarflare
    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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