RK3308内核使能串口1后PC给它发送数据会echo回传，板子给PC发数据正常，求指点

luffycheung

使能uart1在板级DTS文件rk3308-roc-cc-dmic-pdm_emmc.dts里添加以下代码:

1. &fiq_debugger {
   
2.     status = "okay";
   
3.     pinctrl-names = "default";
   
4.     pinctrl-0 = <&uart2m0_xfer>;
   
5. };
   
6. 
   
7. 
   
8. &uart1 {
   
9.     status = "okay";
   
10. };
    

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编译下载后内核打印错误信息如下：

1. [    0.381267] Serial: 8250/16550 driver, 5 ports, IRQ sharing disabled
   
2. [    0.383212] rockchip-pinctrl pinctrl: pin gpio1-22 already requested by fiq-debugger; cannot claim for ff0b0000.serial
   
3. [    0.383250] rockchip-pinctrl pinctrl: pin-54 (ff0b0000.serial) status -22
   
4. [    0.383268] rockchip-pinctrl pinctrl: could not request pin 54 (gpio1-22) from group uart1-cts  on device rockchip-pinctrl
   
5. [    0.383283] dw-apb-uart ff0b0000.serial: Error applying setting, reverse things back
   
6. [    0.383719] ff0b0000.serial: ttyS1 at MMIO 0xff0b0000 (irq = 12, base_baud = 5078125) is a 16550A
   
7. [    0.384785] ff0e0000.serial: ttyS4 at MMIO 0xff0e0000 (irq = 13, base_baud = 5078125) is a 16550A
   
8. [    0.386688] [drm] Initialized drm 1.1.0 20060810

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UART SDK文档里说：
设备正常注册就是以上log，如果pinctrl跟其他驱动有冲突的话，会报pinctrl配置失败的log。

我这有冲突的话，该怎么修改呢，求解答

luffycheung

已解决。

打印pinctr错误--> uart1需要重写pinctrl选项，去掉cts和rts。

echo回传现象 --> 由于rk3308终端下执行了cat /dev/ttyS1命令所至。重启rk3308后pc串口软件下发数据正常。
最终dts配置如下，也使能了uart0:

1. &fiq_debugger {
   
2.     status = "okay";
   
3.     pinctrl-names = "default";
   
4.     pinctrl-0 = <&uart2m0_xfer>;
   
5. };
   
6. 
   
7. &uart0 {
   
8.     status = "okay";
   
9. };
   
10. 
    
11. &uart1 {
    
12.     pinctrl-names = "default";
    
13.     pinctrl-0 = <&uart1_xfer>;
    
14.     status = "okay";
    
15. };
    

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