Issue description:
When work on rs485 mode, it can not receive data.
The root casue is the rts can not change,it always pull high.
It can send data only.
Upstream:f85e04503f369b3f2be28c83fc48b74e19936ebc has fixed this issue before.
But d3b3404df318504ec084213ab1065b73f49b0f1d has broken the fix.
Pick the commit:2dd8a74fddd21b95dcc60a2d3c9eaec993419d69 to fix it
Issue description: When work on rs485 mode, it can not receive data. The root casue is the rts can not change,it always pull high. It can send data only.
Upstream:f85e04503f369b3f2be28c83fc48b74e19936ebc has fixed this issue before. But d3b3404df318504ec084213ab1065b73f49b0f1d has broken the fix. Pick the commit:2dd8a74fddd21b95dcc60a2d3c9eaec993419d69 to fix it
Signed-off-by: chao zeng chao.zeng@siemens.com