CH341 driver does not work properly with RS1221+

[chenzhuoyu]

Receiving from serial port is unreliable, the character won't show up until it "buffered" enough of it, about 32 characters.

I rebuilt the driver with this version of ch341.c and the problem is gone.

ch341.c@f2950b7

So would you please update the source?

[robertklep]

Which platform/kernel version did you use?

[chenzhuoyu]

@robertklep v1000 with Linux 4.4.x

My setup is Synology RS1221+ with AMD Ryzen V1500, connected to Schneider SPRM1k UPS via USB cable. The USB is essentially an CH341 USB to Serial converter built into the UPS.

[chenzhuoyu]

Also it looks like it's missing a build file SynoBuildConf/build

[chenzhuoyu]

@robertklep Any updates on this?

[robertklep]

@chenzhuoyu I'm not sure how I should handle this.

I can replace the driver file but this would then apply to all platforms using the 4.4.x kernel, not just v1000. And AFAIK, you're the only one that has come forward with this issue, so it might be something local.