Thanks Drew! This helps alot!
Bob
On Tue, May 29, 2001 at 05:00:43PM -0400, Andrew Gallatin wrote:
>
>
> Jesper Skriver writes:
> > On Tue, May 29, 2001 at 02:41:14PM -0500, Bob Willcox wrote:
> > > Hi,
> > >
> > > I am working on a device driver for a GSN adapter that has hardware CRC
> > > checking and need to know if there is a way to disable the software CRC
> > > checking for TCP? This is on a FreeBSD 4.2-stable system.
> >
>
> Eegads. I think the original poster wanted to be able to use the
> hardware CRC features of his nic, not ignore checksums altogther.
>
> Bob -- Take a look at the /sys/pci/if_ti.c driver for an example of
> how to use hardware checksum assist.
>
> On the recieve side, you want to set the m_pkthdr.csum_flags
> appropriately (depending on what your device can do) on each recieve,
> as well as fill in the actual checksum in m_pkthdr.csum_data.
>
> On the send side, you need to specify what your device is capable of
> assisting with in the if_hwassist field of your driver's ifp struct.
> Packets will come down w/o those fields filled in. The stack will
> expect your device to calculate those fields in hardware.
>
> I beleive these features appeared around 4.1, so if this is a 3rd
> party driver, you may want to check __FreeBSD_version >= 410000.
>
>
> Hope this helps,
>
> Drew
>
> ------------------------------------------------------------------------------
> Andrew Gallatin, Sr Systems Programmer http://www.cs.duke.edu/~gallatin
> Duke University Email: [EMAIL PROTECTED]
> Department of Computer Science Phone: (919) 660-6590
--
Bob Willcox Egotist, n.:
[EMAIL PROTECTED] A person of low taste, more interested in himself than me.
Austin, TX -- Ambrose Bierce, "The Devil's Dictionary"
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-hackers" in the body of the message
