arm64: dts: rockchip: Add dma-names to uart1 on quartz64-b

There have been several attempts to set the dma-names property on the
SoC level (in rk356x.dtsi), but that appears to cause problems when set
on channels without flow control.

Quoting part of a previous attempt for clarification:

> Nah, enabling it for bluetooth is fine because you have flow control.
> My issues have been on channels without flow control. Without DMA it
> simply drops messages or the channel hangs until you close and reopen
> it. With DMA, when an overflow locks up the channel it is usually
> unavailable until the board is rebooted.

Setting it on the board level for the bluetooth connection was deemed
safe, so do so for the Quartz64 Model B.

This fixes the following error/warning:

  of_dma_request_slave_channel: dma-names property of node
      '/serial@fe650000' missing or empty
  dw-apb-uart fe650000.serial: failed to request DMA

Signed-off-by: Diederik de Haas <didi.debian@cknow.org>
Link: https://libera.irclog.whitequark.org/armlinux/2024-02-29
Link: https://lore.kernel.org/linux-rockchip/18284546.sWSEgdgrri@diego/
Reviewed-by: Dragan Simic <dsimic@manjaro.org>
Link: https://lore.kernel.org/r/20240628120130.24076-1-didi.debian@cknow.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

diff --git a/arch/arm64/boot/dts/rockchip/rk3566-quartz64-b.dts b/arch/arm64/boot/dts/rockchip/rk3566-quartz64-b.dts
index 26322a358d919a5c732a3d86cd79915aa38e9cb3..a9dd60464b3feffa8e1e18cb6ea55cf6be3a1cd7 100644 (file)
--- a/arch/arm64/boot/dts/rockchip/rk3566-quartz64-b.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3566-quartz64-b.dts
@@ -652,6 +652,7 @@
 };
 
 &uart1 {
+       dma-names = "tx", "rx";
        pinctrl-names = "default";
        pinctrl-0 = <&uart1m0_xfer &uart1m0_ctsn &uart1m0_rtsn>;
        status = "okay";