linux/drivers/spi
Vignesh R b6e44f7439 spi: omap2-mcspi: Set FIFO DMA trigger level to word length
[ Upstream commit b682cffa3a ]

McSPI has 32 byte FIFO in Transmit-Receive mode. Current code tries to
configuration FIFO watermark level for DMA trigger to be GCD of transfer
length and max FIFO size which would mean trigger level may be set to 32
for transmit-receive mode if length is aligned. This does not work in
case of SPI slave mode where FIFO always needs to have data ready
whenever master starts the clock. With DMA trigger size of 32 there will
be a small window during slave TX where DMA is still putting data into
FIFO but master would have started clock for next byte, resulting in
shifting out of stale data. Similarly, on Slave RX side there may be RX
FIFO overflow
Fix this by setting FIFO watermark for DMA trigger to word
length. This means DMA is triggered as soon as FIFO has space for word
length bytes and DMA would make sure FIFO is almost always full
therefore improving FIFO occupancy in both master and slave mode.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:16:43 +01:00
..
internals.h spi: Add an helper to flush the message queue 2018-04-23 15:48:18 +01:00
Kconfig spi: add SPI controller driver for UniPhier SoC 2018-08-01 11:22:37 +01:00
Makefile spi: add SPI controller driver for UniPhier SoC 2018-08-01 11:22:37 +01:00
spi-altera.c
spi-armada-3700.c Merge remote-tracking branches 'spi/topic/a3700', 'spi/topic/atmel', 'spi/topic/bcm53xx', 'spi/topic/davinci' and 'spi/topic/dw' into spi-next 2018-01-26 17:57:24 +00:00
spi-ath79.c spi: add flags parameter to txrx_word function pointers 2018-08-01 14:50:24 +01:00
spi-atmel.c spi: spi-atmel: Use correct enum for DMA transfer direction 2018-03-28 10:42:48 +08:00
spi-au1550.c
spi-axi-spi-engine.c spi: spi-axi: fix potential use-after-free after deregistration 2017-10-31 11:15:10 +00:00
spi-bcm-qspi.c spi: bcm-qspi: fix calculation of address length 2018-11-13 11:08:15 -08:00
spi-bcm-qspi.h
spi-bcm63xx-hsspi.c spi/bcm63xx-hsspi: keep pll clk enabled 2019-11-20 18:46:54 +01:00
spi-bcm63xx.c
spi-bcm2835.c spi: bcm2835: Fix 3-wire mode if DMA is enabled 2019-08-09 17:52:35 +02:00
spi-bcm2835aux.c spi: bcm2835aux: fix corruptions for longer spi transfers 2019-09-10 10:33:41 +01:00
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 spi: bitbang: Fix NULL pointer dereference in spi_unregister_master 2019-07-10 09:53:32 +02:00
spi-brcmstb-qspi.c
spi-butterfly.c spi: add flags parameter to txrx_word function pointers 2018-08-01 14:50:24 +01:00
spi-cadence.c spi: cadence: Fix missing clk_disable_unprepare() on error in cnds_runtime_resume() 2018-07-11 15:34:53 +01:00
spi-cavium-octeon.c
spi-cavium-thunderx.c
spi-cavium.c
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-coldfire-qspi.c
spi-davinci.c Merge branch 'spi-4.18' into spi-linus 2018-08-10 17:51:50 +01:00
spi-dln2.c
spi-dw-mid.c spi: dw: Convert to generalized SPI controller API 2018-02-12 12:04:16 +00:00
spi-dw-mmio.c spi: dw-mmio: add MSCC Ocelot support 2018-07-30 12:02:08 +01:00
spi-dw-pci.c
spi-dw.c Merge branch 'spi-4.19' into spi-next 2018-08-10 17:51:52 +01:00
spi-dw.h spi: dw: export dw_spi_set_cs 2018-07-30 12:02:07 +01:00
spi-efm32.c
spi-ep93xx.c spi: spi-ep93xx: Use dma_data_direction for ep93xx_spi_dma_{finish,prepare} 2018-11-13 11:08:22 -08:00
spi-falcon.c
spi-fsl-cpm.c
spi-fsl-cpm.h
spi-fsl-dspi.c spi: spi-fsl-dspi: fix broken DSPI_EOQ_MODE 2018-08-28 20:55:23 +01:00
spi-fsl-espi.c spi: spi-fsl-espi: Log fifo counters on error 2018-07-26 15:43:09 +01:00
spi-fsl-lib.c
spi-fsl-lib.h
spi-fsl-lpspi.c spi: fsl-lpspi: Prevent FIFO under/overrun by default 2019-11-24 08:20:55 +01:00
spi-fsl-spi.c
spi-fsl-spi.h
spi-gpio.c spi: spi-gpio: fix SPI_CS_HIGH capability 2019-09-16 08:22:07 +02:00
spi-img-spfi.c spi: img-spfi: Set device select bits for SPFI port state 2018-07-30 16:31:54 +01:00
spi-imx.c spi: imx: stop buffer overflow in RX FIFO flush 2019-05-31 06:46:34 -07:00
spi-iproc-qspi.c
spi-jcore.c spi: jcore: disable ref_clk after getting its rate 2018-03-18 17:57:42 -07:00
spi-lantiq-ssc.c
spi-lm70llp.c spi: add flags parameter to txrx_word function pointers 2018-08-01 14:50:24 +01:00
spi-loopback-test.c
spi-lp8841-rtc.c
spi-mem.c spi: spi-mem: Adjust op len based on message/transfer size limitations 2018-11-13 11:08:15 -08:00
spi-meson-spicc.c spi: meson-spicc: Fix error handling in meson_spicc_probe() 2018-05-02 05:59:21 +09:00
spi-meson-spifc.c
spi-mpc52xx-psc.c
spi-mpc52xx.c spi: mpc52xx: Use gpio_is_valid() 2018-04-27 12:05:39 +01:00
spi-mpc512x-psc.c
spi-mt65xx.c spi: mediatek: use correct mata->xfer_len when in fifo transfer 2019-11-24 08:19:06 +01:00
spi-mxs.c spi: mxs: Switch to SPDX identifier 2018-05-03 10:27:43 +09:00
spi-nuc900.c
spi-oc-tiny.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
spi-omap-100k.c
spi-omap-uwire.c
spi-omap2-mcspi.c spi: omap2-mcspi: Set FIFO DMA trigger level to word length 2019-12-01 09:16:43 +01:00
spi-orion.c spi: orion: fix CS GPIO handling again 2018-06-19 13:06:51 +01:00
spi-pic32-sqi.c
spi-pic32.c spi: pic32: Use proper enum in dmaengine_prep_slave_rg 2019-11-20 18:47:11 +01:00
spi-pl022.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
spi-ppc4xx.c
spi-pxa2xx-dma.c spi: pxa2xx: Use core message processing loop 2018-04-17 17:11:30 +01:00
spi-pxa2xx-pci.c
spi-pxa2xx.c dmaengine: idma64: Use actual device for DMA transfers 2019-06-15 11:54:10 +02:00
spi-pxa2xx.h spi: pxa2xx: Allow 64-bit DMA 2018-04-24 16:10:12 +01:00
spi-qup.c
spi-rb4xx.c
spi-rockchip.c spi: rockchip: initialize dma_slave_config properly 2019-11-24 08:21:05 +01:00
spi-rspi.c spi: rspi: Fix sequencer reset during initialization 2019-05-31 06:46:34 -07:00
spi-s3c24xx-fiq.h
spi-s3c24xx-fiq.S
spi-s3c24xx.c
spi-s3c64xx.c spi: spi-s3c64xx: Fix system resume support 2018-05-17 13:27:08 +09:00
spi-sc18is602.c
spi-sh-hspi.c
spi-sh-msiof.c spi: sh-msiof: fix deferred probing 2019-12-01 09:16:20 +01:00
spi-sh-sci.c spi: add flags parameter to txrx_word function pointers 2018-08-01 14:50:24 +01:00
spi-sh.c
spi-sirf.c spi: sirf: account for const type of of_device_id.data 2018-01-03 11:38:46 +00:00
spi-slave-system-control.c
spi-slave-time.c
spi-sprd-adi.c spi: sprd: Change to use devm_hwspin_lock_request_specific() 2018-06-26 13:52:27 -07:00
spi-st-ssc4.c
spi-stm32.c spi: stm32: Fix error handling in stm32_spi_probe() 2018-04-17 11:46:23 +01:00
spi-sun4i.c spi: sun4i: disable clocks in the remove function 2017-12-07 11:59:15 +00:00
spi-sun6i.c spi: sun6i: disable/unprepare clocks on remove 2017-12-07 17:45:17 +00:00
spi-tegra20-sflash.c
spi-tegra20-slink.c spi: tegra20-slink: explicitly enable/disable clock 2018-09-03 12:23:41 +01:00
spi-tegra114.c spi: tegra114: reset controller on probe 2019-05-31 06:46:28 -07:00
spi-test.h
spi-ti-qspi.c spi: ti-qspi: Fix mmap read when more than one CS in use 2019-03-23 20:09:57 +01:00
spi-tle62x0.c
spi-topcliff-pch.c spi : spi-topcliff-pch: Fix to handle empty DMA buffers 2019-05-31 06:46:33 -07:00
spi-txx9.c
spi-uniphier.c spi: uniphier: remove unnecessary include headers 2018-08-02 11:08:06 +01:00
spi-xcomm.c
spi-xilinx.c spi: xilinx: Add support for xlnx,axi-quad-spi-1.00.a 2017-11-27 16:31:20 +00:00
spi-xlp.c
spi-xtensa-xtfpga.c spi: add flags parameter to txrx_word function pointers 2018-08-01 14:50:24 +01:00
spi-zynqmp-gqspi.c spi: simplify getting .drvdata 2018-04-20 17:53:20 +01:00
spi.c spi: Fix zero length xfer bug 2019-05-31 06:46:34 -07:00
spidev.c spi: spidev: Fix OF tree warning logic 2019-11-24 08:20:56 +01:00