ar71xx: boost SPI flash read performance

mtd_speedtest results:
                           page read speed
                    old         new        delta
DB120            929 KiB/s   2597 KiB/s   +179.55%
TL-WR1043ND v1   754 KiB/s   2166 KiB/s   +187.27%
TL-WR703N v1     745 KiB/s   2176 KiB/s   +192.08%
TL-MR3220 v1     752 KiB/s   2154 KiB/s   +186.44%
TL-WR2543ND v1   564 KiB/s   2130 KiB/s   +277.66%
TL-WR741ND v2    525 KiB/s   1767 KiB/s   +236.57%
ALFA-AP96        702 KiB/s   1977 KiB/s   +181.62%
WNDR3700         697 KiB/s   1965 KiB/s   +181.92%

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@31118 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 23 insertions, 0 deletions

diff --git a/target/linux/ar71xx/patches-3.2/461-spi-add-type-field-to-spi_transfer.patch b/target/linux/ar71xx/patches-3.2/461-spi-add-type-field-to-spi_transfer.patch
new file mode 100644
index 000000000..e87d7fc0f
--- /dev/null
+++ b/target/linux/ar71xx/patches-3.2/461-spi-add-type-field-to-spi_transfer.patch
@@ -0,0 +1,23 @@
+--- a/include/linux/spi/spi.h
++++ b/include/linux/spi/spi.h
+@@ -344,6 +344,12 @@ extern struct spi_master *spi_busnum_to_
+ 
+ /*---------------------------------------------------------------------------*/
+ 
++enum spi_transfer_type {
++	SPI_TRANSFER_GENERIC = 0,
++	SPI_TRANSFER_FLASH_READ_CMD,
++	SPI_TRANSFER_FLASH_READ_DATA,
++};
++
+ /*
+  * I/O INTERFACE between SPI controller and protocol drivers
+  *
+@@ -446,6 +452,7 @@ struct spi_transfer {
+ 	u8		bits_per_word;
+ 	u16		delay_usecs;
+ 	u32		speed_hz;
++	enum spi_transfer_type type;
+ 
+ 	struct list_head transfer_list;
+ };