Re: [PATCH] arm64: dts: rockchip: Add uart dma names to the SoC dtsi for RK356x

[Dragan Simic <dsimic@manjaro.org>]

Hello Philipp,

On 2024-07-10 12:20, Philipp Puschmann wrote:
> 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@cknow.org/
> 
> 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.

 From what I've read in the prior discussions, this seems like a driver
issue, so the driver should be fixed instead.

>> 
>>> Signed-off-by: Philipp Puschmann <p.puschmann@pironex.com>
>>> ---
>>>  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>;
>>> ...
> 
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rockchip