kernel_optimize_test/drivers/spi
Trent Piepho a560943ead spi: spi-mxs: Don't set clock for each xfer
mxs_spi_setup_transfer() would set the SSP SCK rate every time it was
called, which is before every transfer.  It is uncommon for the SCK rate to
change between transfers (or at all of that matter) and this causes many
unnecessary reprogrammings of the clock registers.

Code changed to only set the rate when it changes.  This significantly
speeds up short SPI messages, especially messages made up of many transfers,
as the calculation of the clock divisors is rather costly.  On an iMX287,
using spidev with messages that consist of 511 transfers of 4 bytes each at
an SCK of 48 MHz, the effective transfer rate more than doubles from about
290 KB/sec to 600 KB/sec!

Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-10-18 01:00:32 +01:00
..
Kconfig Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
Makefile Merge remote-tracking branch 'spi/topic/qspi' into spi-next 2013-09-01 13:49:06 +01:00
spi-altera.c ARM: SoC DT updates for 3.12 2013-09-06 13:26:27 -07:00
spi-ath79.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-atmel.c spi: atmel: Fix incorrect error path 2013-10-07 12:36:01 +01:00
spi-au1550.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-bcm63xx.c Merge remote-tracking branch 'spi/topic/qspi' into spi-next 2013-09-01 13:49:06 +01:00
spi-bcm2835.c spi: bcm2835: Add spi_master_get() call to prevent use after free 2013-08-22 19:07:51 +01:00
spi-bfin-sport.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-bfin-v3.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-bfin5xx.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-bitbang-txrx.h
spi-bitbang.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-09-06 09:36:28 -07:00
spi-butterfly.c
spi-clps711x.c spi/clps711x: drop clk_put for devm_clk_get in spi_clps711x_probe() 2013-09-27 10:49:09 +01:00
spi-coldfire-qspi.c Merge remote-tracking branch 'spi/topic/qspi' into spi-next 2013-09-01 13:49:06 +01:00
spi-davinci.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-dw-mid.c
spi-dw-mmio.c
spi-dw-pci.c
spi-dw.c
spi-dw.h
spi-efm32.c spi: efm32: Fix build error 2013-08-31 16:29:14 +01:00
spi-ep93xx.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-falcon.c
spi-fsl-cpm.c
spi-fsl-cpm.h
spi-fsl-dspi.c spi: fix return value check in dspi_probe() 2013-09-12 10:53:16 +01:00
spi-fsl-espi.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-fsl-lib.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-fsl-lib.h
spi-fsl-spi.c PTR_RET() is a weird name, and led to some confusing usage. We ended 2013-09-04 17:31:11 -07:00
spi-fsl-spi.h
spi-gpio.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-imx.c
spi-lm70llp.c
spi-mpc52xx-psc.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-mpc52xx.c
spi-mpc512x-psc.c spi: mpc512x: fix error return code in mpc512x_psc_spi_do_probe() 2013-09-12 10:48:57 +01:00
spi-mxs.c spi: spi-mxs: Don't set clock for each xfer 2013-10-18 01:00:32 +01:00
spi-nuc900.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-oc-tiny.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-octeon.c spi: octeon: Convert to use bits_per_word_mask 2013-08-20 11:34:08 +01:00
spi-omap-100k.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-omap-uwire.c
spi-omap2-mcspi.c Merge remote-tracking branch 'spi/topic/qspi' into spi-next 2013-09-01 13:49:06 +01:00
spi-orion.c Merge remote-tracking branch 'spi/topic/orion' into spi-next 2013-09-01 13:49:02 +01:00
spi-pl022.c Merge remote-tracking branch 'spi/topic/qspi' into spi-next 2013-09-01 13:49:06 +01:00
spi-ppc4xx.c
spi-pxa2xx-dma.c
spi-pxa2xx-pci.c
spi-pxa2xx-pxadma.c
spi-pxa2xx.c spi/pxa2xx: check status register as well to determine if the device is off 2013-09-04 20:14:29 +01:00
spi-pxa2xx.h
spi-rspi.c Merge remote-tracking branch 'spi/topic/rspi' into spi-next 2013-09-01 13:49:08 +01:00
spi-s3c24xx-fiq.h
spi-s3c24xx-fiq.S
spi-s3c24xx.c spi: Use dev_get_drvdata at appropriate places 2013-08-29 13:57:14 +01:00
spi-s3c64xx.c spi/s3c64xx: Ensure runtime PM is enabled prior to registration 2013-09-27 14:26:04 +01:00
spi-sc18is602.c
spi-sh-hspi.c spi/hspi: fixup Runtime PM enable timing 2013-10-03 14:08:06 +01:00
spi-sh-msiof.c Merge remote-tracking branch 'spi/topic/sh-msiof' into spi-next 2013-09-01 13:49:11 +01:00
spi-sh-sci.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-sh.c
spi-sirf.c Merge remote-tracking branch 'spi/topic/sirf' into spi-next 2013-09-01 13:49:12 +01:00
spi-tegra20-sflash.c
spi-tegra20-slink.c
spi-tegra114.c Merge remote-tracking branch 'spi/topic/tegra' into spi-next 2013-09-01 13:49:13 +01:00
spi-ti-qspi.c spi/qspi: fix missing unlock on error in ti_qspi_start_transfer_one() 2013-09-01 13:47:55 +01:00
spi-ti-ssp.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-tle62x0.c Merge remote-tracking branch 'spi/topic/tel62x0' into spi-next 2013-09-01 13:49:14 +01:00
spi-topcliff-pch.c
spi-txx9.c
spi-xcomm.c
spi-xilinx.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi.c Merge remote-tracking branch 'spi/topic/quad' into spi-next 2013-09-01 13:49:07 +01:00
spidev.c