Re: [PATCH 3/3] NetXen: 64-bit memory fixes, driver cleanup

[Sanjeev Jorapur <sanjeev@netxen.com>]

On Mon, 2006-11-20 at 10:45 -0800, Stephen Hemminger wrote:
> On Sat, 18 Nov 2006 15:58:09 +0530
> Sanjeev Jorapur <sanjeev@netxen.com> wrote:
> 
> > On Fri, 2006-11-17 at 08:40 -0800, Stephen Hemminger wrote:
> > > On Fri, 17 Nov 2006 07:36:03 -0800
> > > "Linsys Contractor Amit S. Kale" <amitkale@netxen.com> wrote:
> > > 
> > > > NetXen: 1G/10G Ethernet Driver updates
> > > > 	- These fixes take care of driver on machines with >4G memory
> > > > 	- Driver cleanup
> > > > 
> > > > Signed-off-by: Amit S. Kale <amitkale@netxen.com>
> > > > 
> > > >  netxen_nic.h          |   41 ++++++----
> > > >  netxen_nic_ethtool.c  |   19 ++--
> > > >  netxen_nic_hw.c       |   10 +-
> > > >  netxen_nic_hw.h       |    4 
> > > >  netxen_nic_init.c     |   51 +++++++++++-
> > > >  netxen_nic_isr.c      |    3 
> > > >  netxen_nic_main.c     |  204 +++++++++++++++++++++++++++++++++++++++++++++++---
> > > >  netxen_nic_phan_reg.h |   10 +-
> > > >  8 files changed, 293 insertions(+), 49 deletions(-)
> > > > 
> > > 
> > > 
> > > If you can't DMA from high memory, then don't set NETIF_F_HIGHDMA, why do
> > > you need explicit bounce buffers.  If you can't DMA from unaligned address,
> > > the write a small routine to copy the skb to a new one.
> > 
> > 
> > The hardware supports DMA into 35 bit addresses. The intent is to
> > enable DMA into addresses upto 32G.
> > 
> 
> You should then set the same value for pci_set_dma_mask, because then the IOMMU
> can help. See both b44 or tg3 drivers, they have to deal with odd size masks.
> I don't think you have to do all the bounce buffer work in the driver.
> 

We had tried something like this earlier, but found that on some
platforms (Opteron, IA64), we got kernel panics when the kernel
ran out of translation entries.

We will re-try this and let you know.

Sanjeev.