Messages in this thread | | | Subject | Re: [PATCH] drivers/net/usb/asix: resync from vendor's copy | From | Ben Hutchings <> | Date | Wed, 9 Nov 2011 17:48:15 +0000 |
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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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