[PATCH] ARM: dts: rockchip: Add dmac_bus rx and tx for uart2
Heiko Stuebner
heiko at sntech.de
Tue Jun 16 04:37:33 PDT 2015
Hi,
Am Montag, 15. Juni 2015, 17:47:48 schrieb Romain Perier:
> This removes warning "ttyS2 - Failed to request dma" from kernel logs
>
> Signed-off-by: Romain Perier <romain.perier at gmail.com>
> ---
> arch/arm/boot/dts/rk3288.dtsi | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi
> index 22316d0..816f40a 100644
> --- a/arch/arm/boot/dts/rk3288.dtsi
> +++ b/arch/arm/boot/dts/rk3288.dtsi
> @@ -385,6 +385,8 @@
> clock-names = "baudclk", "apb_pclk";
> pinctrl-names = "default";
> pinctrl-0 = <&uart2_xfer>;
> + dmas = <&dmac_bus_s 4>, <&dmac_bus_s 5>;
> + dma-names = "tx", "rx";
> status = "disabled";
> };
The dma channels are a property of the hardware, so we probably should add
them for all uarts in one go, instead of everytime something complains :-)
in dmac_peri
uart0: tx 1, rx 2
uart1: tx 3, rx 4
uart3: tx 7, rx 8
uart4: tx 9, rx 10
Just for the record and if anybody is interested to work in this, we have an
issue with the dma implementation [0] that is not yet solved upstream. From
what I've remember, that mostly got triggered on higher speeds, like higher
spi-speeds or i2s audio stuff (poping).
Heiko
[0]
https://chromium.googlesource.com/chromiumos/third_party/kernel/+/93c3b192dca7e8c773c4d28873114c325382b63e%5E%21/#F0
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