AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-12-15 13:36:43 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity
3c0f9d8bcf
linux_dsm_epyc7002/drivers/spi
History
Vladimir Oltean 3c0f9d8bcf
spi: spi-fsl-dspi: Always use the TCFQ devices in poll mode 
With this patch, the "interrupts" property from the device tree bindings
is ignored, even if present, if the driver runs in TCFQ mode.

Switching to using the DSPI in poll mode has several distinct
benefits:

- With interrupts, the DSPI driver in TCFQ mode raises an IRQ after each
  transmitted word. There is more time wasted for the "waitq" event than
  for actual I/O. And the DSPI IRQ count can easily get the largest in
  /proc/interrupts on Freescale boards with attached SPI devices.

- The SPI I/O time is both lower, and more consistently so. Attached to
  some Freescale devices are either PTP switches, or SPI RTCs. For
  reading time off of a SPI slave device, it is important that all SPI
  transfers take a deterministic time to complete.

- In poll mode there is much less time spent by the CPU in hardirq
  context, which helps with the response latency of the system, and at
  the same time there is more control over when interrupts must be
  disabled (to get a precise timestamp measurement, which will come in a
  future patch): win-win.

On the LS1021A-TSN board, where the SPI device is a SJA1105 PTP switch
(with a bits_per_word=8 driver), I created a "benchmark" where I
periodically transferred a 12-byte message once per second, for 120
seconds. I then recorded the time before putting the first byte in the
TX FIFO, and the time after reading the last byte from the RX FIFO. That
is the transfer delay in nanoseconds.

Interrupt mode:

  delay: min 125120 max 168320 mean 150286 std dev 17675.3

Poll mode:

  delay: min 69440 max 119040 mean 70312.9 std dev 8065.34

Both the mean latency and the standard deviation are more than 50% lower
in poll mode than in interrupt mode, and the 'max' in poll mode is lower
than the 'min' in interrupt mode. This is with an 'ondemand' governor on
an otherwise idle system - therefore running mostly at 600 MHz out of a
max of 1200 MHz.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20191001205216.32115-1-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-02 12:59:30 +01:00
..
atmel-quadspi.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
internals.h spi: Add an helper to flush the message queue 2018-04-23 15:48:18 +01:00
Kconfig It's a somewhat calmer cycle for docs this time, as the churn of the mass 2019-09-17 16:22:26 -07:00
Makefile ARM: SoC driver updates for v5.4 2019-09-16 15:52:38 -07:00
spi-altera.c spi: altera: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:14:50 +01:00
spi-armada-3700.c spi: a3700: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:15:09 +01:00
spi-at91-usart.c spi: at91-usart: add DMA support 2019-05-08 17:45:26 +09:00
spi-ath79.c spi: ath79: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:15:29 +01:00
spi-atmel.c spi: atmel: Remove AVR32 leftover 2019-10-01 12:33:39 +01:00
spi-au1550.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
spi-axi-spi-engine.c spi: spi-axi: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:15:49 +01:00
spi-bcm63xx-hsspi.c spi: bcm63xx-hsspi: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:16:47 +01:00
spi-bcm63xx.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
spi-bcm2835.c Merge branch 'spi-5.4' into spi-next 2019-09-15 10:32:06 +01:00
spi-bcm2835aux.c spi: bcm2835aux: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:16:08 +01:00
spi-bcm-qspi.c Merge branch 'spi-5.3' into spi-linus 2019-09-15 10:32:04 +01:00
spi-bcm-qspi.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 459 2019-06-19 17:09:09 +02:00
spi-bitbang-txrx.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
spi-bitbang.c Linux 5.2-rc4 2019-06-10 18:52:53 +01:00
spi-brcmstb-qspi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 459 2019-06-19 17:09:09 +02:00
spi-butterfly.c spi: docs: convert to ReST and add it to the kABI bookset 2019-07-31 14:13:13 -06:00
spi-cadence.c spi: cadence: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:17:07 +01:00
spi-cavium-octeon.c spi: octeon: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:17:27 +01:00
spi-cavium-thunderx.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
spi-cavium.c spi: octeon: Split driver into Octeon specific and common parts 2016-07-24 21:54:29 +01:00
spi-cavium.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
spi-clps711x.c spi: clps711x: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:17:36 +01:00
spi-coldfire-qspi.c spi: coldfire-qspi: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:17:56 +01:00
spi-davinci.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
spi-dln2.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372 2019-06-05 17:37:10 +02:00
spi-dw-mid.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
spi-dw-mmio.c spi: dw: Add compatible string for Renesas RZ/N1 SPI Controller 2019-10-01 12:33:19 +01:00
spi-dw-pci.c SPI: designware: pci: Switch over to MSI interrupts 2019-10-01 18:40:38 +01:00
spi-dw.c spi: dw: Add basic runtime PM support 2019-10-01 12:32:56 +01:00
spi-dw.h dw: spi: add support for Amazon's Alpine spi controller 2018-10-11 15:11:04 +01:00
spi-efm32.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
spi-ep93xx.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
spi-falcon.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-fsl-cpm.c spi: fsl-spi: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:24:26 +01:00
spi-fsl-cpm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
spi-fsl-dspi.c spi: spi-fsl-dspi: Always use the TCFQ devices in poll mode 2019-10-02 12:59:30 +01:00
spi-fsl-espi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
spi-fsl-lib.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
spi-fsl-lib.h spi: fsl: Convert to use CS GPIO descriptors 2019-08-28 14:10:41 +01:00
spi-fsl-lpspi.c spi: fsl-lpspi: clean up indentation issue 2019-10-01 12:36:02 +01:00
spi-fsl-qspi.c spi: spi-fsl-qspi: Introduce variable to fix different invalid master Id 2019-10-01 18:40:17 +01:00
spi-fsl-spi.c spi: fsl: Convert to use CS GPIO descriptors 2019-08-28 14:10:41 +01:00
spi-fsl-spi.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
spi-geni-qcom.c spi: spi-geni-qcom: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:18:25 +01:00
spi-gpio.c spi-gpio: Use PTR_ERR_OR_ZERO() in spi_gpio_request() 2019-09-09 11:05:39 +01:00
spi-img-spfi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 422 2019-06-05 17:37:15 +02:00
spi-imx.c Merge branch 'spi-5.1' into spi-5.2 for stm32 2019-03-15 17:06:34 +00:00
spi-iproc-qspi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
spi-jcore.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
spi-lantiq-ssc.c spi: lantiq-ssc: Use devm_platform_ioremap_resource() in lantiq_ssc_probe() 2019-10-01 12:34:18 +01:00
spi-lm70llp.c spi: docs: convert to ReST and add it to the kABI bookset 2019-07-31 14:13:13 -06:00
spi-loopback-test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
spi-lp8841-rtc.c spi: lp-8841: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:18:35 +01:00
spi-mem.c spi-mem: fix kernel-doc for spi_mem_dirmap_{read|write}() 2019-04-08 14:06:51 +07:00
spi-meson-spicc.c spi: meson-spicc: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:18:55 +01:00
spi-meson-spifc.c spi: spi-meson-spifc: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:19:14 +01:00
spi-mpc52xx-psc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
spi-mpc52xx.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
spi-mpc512x-psc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
spi-mt65xx.c spi: mediatek: Use devm_platform_ioremap_resource() in mtk_spi_probe() 2019-10-01 12:34:38 +01:00
spi-mt7621.c spi: mt7621: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:19:34 +01:00
spi-mxic.c spi: mxic: Ensure width is respected in spi-mem operations 2019-10-01 12:33:58 +01:00
spi-mxs.c spi: mxs: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:19:54 +01:00
spi-npcm-fiu.c spi: npcm-fiu: remove set but not used variable 'retlen' 2019-09-05 18:19:45 +01:00
spi-npcm-pspi.c spi: npcm: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:20:03 +01:00
spi-nxp-fspi.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
spi-oc-tiny.c spi: oc-tiny: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:20:33 +01:00
spi-omap2-mcspi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
spi-omap-100k.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
spi-omap-uwire.c spi: omap-uwire: Remove needless bits_per_word and speed_hz tests 2015-09-17 12:33:58 +01:00
spi-orion.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-pic32-sqi.c spi: pic32-sqi: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:20:52 +01:00
spi-pic32.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
spi-pl022.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
spi-ppc4xx.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-pxa2xx-dma.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-pxa2xx-pci.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
spi-pxa2xx.c spi: pxa2xx: Add support for Intel Tiger Lake 2019-08-02 12:14:23 +01:00
spi-pxa2xx.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-qcom-qspi.c spi: spi-qcom-qspi: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:21:12 +01:00
spi-qup.c Merge branch 'spi-5.3' into spi-next 2019-07-04 17:35:07 +01:00
spi-rb4xx.c spi: rb4xx: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:21:21 +01:00
spi-rockchip.c Linux 5.2-rc4 2019-06-10 18:52:53 +01:00
spi-rspi.c spi: rspi: Fix handling of QSPI code when transmit and receive 2019-05-02 10:38:44 +09:00
spi-s3c24xx-fiq.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-s3c24xx-fiq.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-s3c24xx.c spi: s3c24xx: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:21:31 +01:00
spi-s3c64xx.c spi: spi-s3c64xx: Fix system resume support 2018-05-17 13:27:08 +09:00
spi-sc18is602.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
spi-sh-hspi.c spi: sh-hspi: Replace spi_master by spi_controller 2019-02-08 13:04:19 +00:00
spi-sh-msiof.c spi: sh-msiof: Use devm_platform_ioremap_resource() helper 2019-08-07 14:24:47 +01:00
spi-sh-sci.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-sh.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
spi-sifive.c spi: sifive: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:21:41 +01:00
spi-sirf.c spi: sirf: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:22:00 +01:00
spi-slave-mt27xx.c spi: mediatek: Use devm_platform_ioremap_resource() in mtk_spi_slave_probe() 2019-10-01 12:34:58 +01:00
spi-slave-system-control.c spi: slave: Fix missing break in switch 2018-10-03 16:23:10 +01:00
spi-slave-time.c spi: slave: Add SPI slave handler reporting uptime at previous message 2017-05-26 13:12:04 +01:00
spi-sprd-adi.c spi: sprd: adi: Change hwlock to be optional 2019-07-26 12:24:47 +01:00
spi-sprd.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
spi-st-ssc4.c spi: st-ssc4: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:22:10 +01:00
spi-stm32-qspi.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
spi-stm32.c spi: stm32: return the get_irq error 2019-05-02 10:38:41 +09:00
spi-sun4i.c spi: sun4i: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:22:29 +01:00
spi-sun6i.c spi: sun6i: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:22:49 +01:00
spi-synquacer.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
spi-tegra20-sflash.c spi: tegra: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:22:58 +01:00
spi-tegra20-slink.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
spi-tegra114.c Linux 5.2-rc4 2019-06-10 18:52:53 +01:00
spi-test.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
spi-ti-qspi.c spi: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:15:43 +01:00
spi-tle62x0.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-topcliff-pch.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 285 2019-06-05 17:36:37 +02:00
spi-txx9.c spi: spi-txx9: Add missing clock (un)prepare calls for CCF 2016-08-18 19:10:39 +01:00
spi-uniphier.c Merge branch 'spi-5.4' into spi-next 2019-09-15 10:32:06 +01:00
spi-xcomm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 149 2019-05-30 11:25:18 -07:00
spi-xilinx.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-xlp.c spi: xlp: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:23:28 +01:00
spi-xtensa-xtfpga.c spi: xtensa-xtfpga: Use devm_platform_ioremap_resource() in xtfpga_spi_probe() 2019-10-01 12:35:18 +01:00
spi-zynq-qspi.c spi: zynq-qspi: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:24:07 +01:00
spi-zynqmp-gqspi.c spi: zynqmp: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:23:48 +01:00
spi.c LED updates for 5.4-rc1 2019-09-17 18:40:42 -07:00
spidev.c Linux 5.2-rc4 2019-06-10 18:52:53 +01:00