UART Communication

1

I have a question regarding UART communication on the WP7605.

[Background]
We are using the WP7605 by switching between suspend mode, which puts the OS to sleep, and the ON state.
With the Rev13.3.1 firmware, executing UART communication occasionally caused bit shifts, frequently resulting in garbled data.
Therefore, to prevent garbled data, we were using the command autosuspend_delay_ms before performing UART communication.

・Before launching the legato app, or when exiting suspend:
/sys/devices/platform/msm_serial_hs.0/power/autosuspend_delay_ms -1
・Command when entering suspend:
/sys/devices/platform/msm_serial_hs.0/power/autosuspend_delay_ms 5000

[Question 1]
In Rev.13.3.1, autosuspend_delay_ms was at the following path:
/sys/devices/platform/msm_serial_hs.0/power/autosuspend_delay_ms
Should I use the following path in Rev.17?
/sys/devices/platform/78af000.uart/power/autosuspend_delay_ms

[Question 2]
In Rev.13.3.1, UART communication failed without autosuspend_delay_ms.
However, in Rev.17, it works fine without autosuspend_delay_ms.
Were there any specification changes, such as timing adjustments?

Alternatively, if there is a way to avoid garbled characters in UART communication, please advise.

2

You can see here:

this user says it is OK to set in R17

either you can try to set -1 to “autosuspend_delay_ms”
Or you can use a timer to periodically wake up the UART in the program by tcflow()