Messages in this thread | | | Date | Wed, 9 Jul 2014 15:38:00 -0700 | Subject | Re: [PATCH v8 4/4] drivers: net: Add APM X-Gene SoC ethernet driver support. | From | Iyappan Subramanian <> |
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On Tue, Jun 24, 2014 at 10:34 PM, David Miller <davem@davemloft.net> wrote: > From: Iyappan Subramanian <isubramanian@apm.com> > Date: Fri, 20 Jun 2014 16:18:16 -0700 > >> This patch adds network driver for APM X-Gene SoC ethernet. >> >> Signed-off-by: Iyappan Subramanian <isubramanian@apm.com> >> Signed-off-by: Ravi Patel <rapatel@apm.com> >> Signed-off-by: Keyur Chudgar <kchudgar@apm.com> > > I really don't like how you handle the hardware descriptors in this > driver. > > You copy back and forth between a software format and the hardware > format. That's extremely wasteful and will hurt performance. > > Just use the raw format throughout, you can extract the fields when > you need them.
I agree and I will fix this and resubmit the patches.
> > You also make two passes when building a hardware descriptor: > > 1) write the values > 2) endian swap > > This means you make three memory accesses on every 64-bit word > in every descriptor you setup, this is really inefficient. > > You should just byte swap them in-situ as you build the raw > descriptors.
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