From 5664dd5561850df580414783cf3c8e0aa834c62e Mon Sep 17 00:00:00 2001 From: Baruch Siach Date: Thu, 18 Dec 2008 19:39:14 -0800 Subject: [PATCH] enc28j60: reduce the number of spi transfers in enc28j60_set_bank() A major source of overhead in the enc28j60 driver is the SPI transfers. Each SPI transfer entails two kernel thread context switches. One major source of SPI transfers is the enc28j60_set_bank() functions which runs before every register access. This patch reduces the number of SPI transfers that enc28j60_set_bank() performs in two ways: 1. removes unnecessary bank switch for the registers that are present in all banks 2. when switching from banks 0 or 3 to banks 1 or 2 (i.e. only one bit changes) enc28j60_set_bank() does only one SPI transfer instead of two According to my tests these changes reduce the number of SPI transfers in about 25%. Signed-off-by: Baruch Siach Signed-off-by: David S. Miller --- Reading git-format-patch failed