On Tue, Feb 04, 2020 at 11:02:04PM +0100, jakub nantl wrote: > Hi, > > I have arduino nano (ch341) connected to my pc and after upgrading > kernel to 5.5.x I am getting garbage instead of text while reading it > (with both 5.5.1 and 5.5.2 kernels): > > Feb 4 09:24:20 sopa read.pl[2070]: StX.XXA(aurXXXŅstXC#021XX XJXR > FuX,#027XX#005 > Feb 4 09:24:20 sopa read.pl[2070]: XtX,+XX HXX#026XX go.XXRXXXXXng*Xery > XXX5XUXiXY'XX4 > Feb 4 09:24:20 sopa read.pl[2070]: XP5逮#013XXteXX11XS4 > Feb 4 09:24:20 sopa read.pl[2070]: > XP5逮#013XXhuXZ.XX=6SHX#005XAXXXpXKVX}XXt=MXXj > Feb 4 09:24:20 sopa read.pl[2070]: DXUu X#013X-XXXXXeXNMSX > Feb 4 09:24:20 sopa read.pl[2070]: XP)}XNXC > > with 5.4.17 I get: > > Feb 4 22:43:10 sopa read.pl[2040]: Started (auriol_last) > Feb 4 22:43:11 sopa read.pl[2040]: Reporting every 300s > Feb 4 22:43:11 sopa read.pl[2040]: Uptime: 60 > Feb 4 22:43:11 sopa read.pl[2040]: DATA: sopa-temp=11.21 > Feb 4 22:43:11 sopa read.pl[2040]: DATA: sopa-humidity=60 > Feb 4 22:43:11 sopa read.pl[2040]: DATA: sopa-dewpoint=3.68 > Feb 4 22:43:11 sopa read.pl[2040]: DATA: sopa-pressure=97136 > Feb 4 22:43:11 sopa read.pl[2040]: DATA_END > > any suggestions? There were some fixes to the baudrate handling that went into 5.5 that are likely related to this. These changes provide more accurate output rates, but I have since received one report that it may inadvertently have made the device more sensitive to errors in the input rate. In that case, the reporter switched to a baudrate that matches his actual rate which was 117647 rather than 115200 (i.e. 2.1% error) and that addressed the problem. Which baudrate are you using here? Johan
