From mboxrd@z Thu Jan 1 00:00:00 1970 From: Iyappan Subramanian Subject: Re: [PATCH v8 4/4] drivers: net: Add APM X-Gene SoC ethernet driver support. Date: Wed, 9 Jul 2014 15:38:00 -0700 Message-ID: References: <1403306296-26198-1-git-send-email-isubramanian@apm.com> <1403306296-26198-5-git-send-email-isubramanian@apm.com> <20140624.223442.1599243407487139839.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <20140624.223442.1599243407487139839.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: David Miller Cc: netdev , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Greg KH , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "jcm-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , patches , Ravi Patel , Keyur Chudgar List-Id: devicetree@vger.kernel.org On Tue, Jun 24, 2014 at 10:34 PM, David Miller wrote: > From: Iyappan Subramanian > 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 >> Signed-off-by: Ravi Patel >> Signed-off-by: Keyur Chudgar > > 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. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html