Hi Greg, Jiri, This patch series attempts to fix the issues Eugeniu Rosca reported seeing, where .flush_buffer() interfered with transmit DMA operation[*]. There's a third patch "dmaengine: rcar-dmac: Reject zero-length slave DMA requests", which is related to the issue, but further independent, hence submitted separately. Eugeniu: does this fix the issues you were seeing? Thanks for your comments! [*] '[PATCH 2/6] Revert "arm64: dts: renesas: r8a7796: Enable DMA for SCIF2"' (https://lore.kernel.org/lkml/20190504004258.23574-3-erosca@xxxxxxxxxxxxxx/). Geert Uytterhoeven (2): serial: sh-sci: Fix TX DMA buffer flushing and workqueue races serial: sh-sci: Terminate TX DMA during buffer flushing drivers/tty/serial/sh-sci.c | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) -- 2.17.1 Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds