Hi Diederik, Am 10.07.24 um 12:02 schrieb Diederik de Haas: > On Wednesday, 10 July 2024 11:33:56 CEST Philipp Puschmann wrote: >> DMA names are required by of_dma_request_slave_channel function that is >> called during uart probe. So to enable DMA for uarts add the names as in >> the RK3568 TRM. > > Setting it on channels without flow control apparently causes issues. See > > https://lore.kernel.org/linux-rockchip/20240628120130.24076-1-didi.debian@xxxxxxxxx/ Ah is see. The only problem that i have is to enable/disable dmas by having or not having dma-names properties, where the latter case is followed by kernel error messages. That is very counterintuitive. Maybe a explicit boolean like dma-broken would be better. That could be set on dtsi level as default and deleted on board dts if wanted. With such a boolean we could also prevent the misleading "dma-names property of" error message and replace it with a hint that dma is disabled on purpose. Regards, Philipp Puschmann > >> Signed-off-by: Philipp Puschmann <p.puschmann@xxxxxxxxxxx> >> --- >> arch/arm64/boot/dts/rockchip/rk356x.dtsi | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/arch/arm64/boot/dts/rockchip/rk356x.dtsi >> b/arch/arm64/boot/dts/rockchip/rk356x.dtsi index d8543b5557ee..4ae40661ca6a >> 100644 >> --- a/arch/arm64/boot/dts/rockchip/rk356x.dtsi >> +++ b/arch/arm64/boot/dts/rockchip/rk356x.dtsi >> @@ -489,6 +489,7 @@ uart0: serial@fdd50000 { >> clocks = <&pmucru SCLK_UART0>, <&pmucru PCLK_UART0>; >> clock-names = "baudclk", "apb_pclk"; >> dmas = <&dmac0 0>, <&dmac0 1>; >> + dma-names = "tx", "rx"; >> pinctrl-0 = <&uart0_xfer>; >> pinctrl-names = "default"; >> reg-io-width = <4>; >> @@ -1389,6 +1390,7 @@ uart1: serial@fe650000 { >> clocks = <&cru SCLK_UART1>, <&cru PCLK_UART1>; >> clock-names = "baudclk", "apb_pclk"; >> dmas = <&dmac0 2>, <&dmac0 3>; >> + dma-names = "tx", "rx"; >> pinctrl-0 = <&uart1m0_xfer>; >> pinctrl-names = "default"; >> reg-io-width = <4>; >> ...
