imx6/imx7 uart overrun

[864535720]

Hello everyone
When I use the serial port to send and receive data on imx6d and imx7d, an overrun error occurs when the serial port is sent. The Linux version I use on imx6 is 3.14.52, and the Linux version used on imx7 is 4.9.88.
Reading the previous post, I found that the serial port has overrun problems. Others have also encountered them. After referring to their previous solutions, I found that it did not solve my problem. For example, remove:
dev_err(sport->port.dev, "Rx FIFO overrun\n");
Use dma.
When I use serial port to transmit data on IMX6/IMX7, I use dma for data transmission. However, overrun still occurs. Does the official website have a correct solution for this error? Please explain in detail the cause of overrun. I already know that the serial port is too late to receive data and cause an overrun error. What I want to know is where it is too late to receive.

[Bio_TICFSL]

Hello,

Please disable busfreq, set cpu to performance mode, and disable deep idle by below command.

echo 0 > /sys/devices/soc0/soc/soc\:busfreq/enable

echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

echo 1 > /sys/devices/system/cpu/cpu0/cpuidle/state1/disable

You need these patches for overrun issue in 3.14.52 however those overrun is fixed in latest bsp, try to upgrade.

Regards

[864535720]

Hi,Bio_TICFSL，

      I am on Linux 4.9.88 version, there will be overrun. What should I do with this version?