]> www.infradead.org Git - users/jedix/linux-maple.git/commit
spi: sh-msiof: Double maximum DMA transfer size using two groups
authorGeert Uytterhoeven <geert+renesas@glider.be>
Fri, 16 May 2025 13:32:22 +0000 (15:32 +0200)
committerMark Brown <broonie@kernel.org>
Mon, 19 May 2025 10:55:35 +0000 (11:55 +0100)
commitacb47aa9b1e2f47121cf2233fcaf998151ab5410
tree9e48af20b7a15f596b33411293fcffd6f79ee4c4
parent39d0856f4102b6b61fdc650f90a1d9231e2bab17
spi: sh-msiof: Double maximum DMA transfer size using two groups

The maximum DMA transfer size is limited by the maximum values that can
be written to the word count fields (WDLENx) in the Transmit and Control
Data Registers (SITDR2/SIRDR2).  As all MSIOF variants support
transferring data of multiple (two or four) groups, the maximum size can
be doubled by using two groups instead of one, thus reducing setup
overhead for very large SPI transfers.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/bad522c76b8d225c195433977b22f95015cf2612.1747401908.git.geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
drivers/spi/spi-sh-msiof.c