RIOT/cpu/sam0_common/periph/Kconfig.spi

# Copyright (c) 2020 HAW Hamburg
#
# This file is subject to the terms and conditions of the GNU Lesser
# General Public License v2.1. See the file LICENSE in the top level
# directory for more details.

config SPI_DMA_THRESHOLD_BYTES
    int "SPI DMA threshold (bytes)"
    depends on MODULE_PERIPH_DMA
    depends on MODULE_PERIPH_SPI
    default 16
    help
        Threshold in bytes under which no SPI DMA transfer will be performed.
        Polling will be used instead.
cpu/sam0_common: SPI: don't perform DMA transfer for small buffers Setting up a DMA transfer can take longer than sending out a buffer byte by byte if the buffer is small. DMA only shows advantages for large buffers, using it for every transfer will cause a net slowdown. Since we did not come up with a good way to determine the treshold based on the SPI frequency, just use a fixed buffer for now so that DMA can be used without slowing things down overall. 2021-10-01 12:41:03 +02:00			`# Copyright (c) 2020 HAW Hamburg`
			`#`
			`# This file is subject to the terms and conditions of the GNU Lesser`
			`# General Public License v2.1. See the file LICENSE in the top level`
			`# directory for more details.`

			`config SPI_DMA_THRESHOLD_BYTES`
			`int "SPI DMA threshold (bytes)"`
			`depends on MODULE_PERIPH_DMA`
			`depends on MODULE_PERIPH_SPI`
			`default 16`
			`help`
			`Threshold in bytes under which no SPI DMA transfer will be performed.`
			`Polling will be used instead.`