Messages in this thread | | | Date | Thu, 07 May 2015 16:24:27 +0300 | From | Sergei Shtylyov <> | Subject | Re: [PATCH] net: usb: allow MTU that is a multiple of USB packet size |
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Hello.
On 5/7/2015 12:49 PM, Ruslan Bilovol wrote:
> Current usbnet driver rejects setting MTU that is a multiple > of USB endpoint's wMaxPacketSize size. However, it may only > lead to possible performance degradation but is not so > critical that its using should be prohibited. So allow it > but also warn user about possible issue.
> Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com> > --- > drivers/net/usb/usbnet.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-)
> diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c > index 733f4fe..09dc848 100644 > --- a/drivers/net/usb/usbnet.c > +++ b/drivers/net/usb/usbnet.c > @@ -382,9 +382,11 @@ int usbnet_change_mtu (struct net_device *net, int new_mtu) > > if (new_mtu <= 0) > return -EINVAL; > - // no second zero-length packet read wanted after mtu-sized packets > + /* warn about second zero-length packet read after mtu-sized packets */ > if ((ll_mtu % dev->maxpacket) == 0) > - return -EDOM; > + netdev_warn(dev->net, "MTU %d is a multiple of USB wMaxPacketSize (%d)," > + " consider possible performance degradation\n",
Please do not wrap the kernel messages, it impedes grepping for them. scripts/checkpatch.pl is aware of this rule.
WBR, Sergei
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