Hi,
This patch series adds DT DMA support to the Renesas "SCI" serial driver
on R-Car Gen2 SoCs.
It depends on "[PATCH v3 00/33] serial: sh-sci: Miscellaneous
and DMA Improvements", which contains preparatory patches that are
considered stable.
Some of these patches have been sent before, cfr.
- [PATCH/RFC v2 00/29] serial: sh-sci: Miscellaneous and DMA
Improvements (http://www.spinics.net/lists/linux-sh/msg43567.html)
- [PATCH/RFC 0/8] serial: sh-sci: Add DT DMA support
(http://www.spinics.net/lists/linux-sh/msg42258.html)
Major change is the replacement of the one-byte DMA transfer on (H)SCIF
by submitting receive DMA requests from the receive interrupt handler.
This was tested on r8a7791/koelsch, using SCIF, SCIFA, SCIFB, and HSCIF.
It should work with and without CONFIG_HIGHMEM (thanks to Shimoda-san).
There are still some known issues in case of overrun errors.
For your convenience, I've also pushed this to
git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git#scif-dma-v3
While it doesn't seem to be a hard requirement, I included the fixed
version of "dmaengine: rcar-dmac: Fix residue reporting for pending
descriptors".
Note that SCI DMA support was originally written for SH-based systems,
and was never fully wired up in platform code in mainline, so the risk
for regressions is fairly small.
Thanks for your comments!
Geert Uytterhoeven (4):
serial: sh-sci: Stop TX and RX on shutdown
serial: sh-sci: Get rid of the workqueue to handle receive DMA
requests
serial: sh-sci: Submit RX DMA from RX interrupt on (H)SCIF
serial: sh-sci: Add DT support to DMA setup
drivers/tty/serial/sh-sci.c | 254 +++++++++++++++++++++++---------------------
1 file changed, 133 insertions(+), 121 deletions(-)
--
1.9.1
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
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