On Mon, Jun 05, 2023 at 09:15:28AM +0200, Johan Hovold wrote: > On Sun, Jun 04, 2023 at 03:11:43PM -0500, Corey Minyard wrote: > > On Sun, Jun 04, 2023 at 02:17:16PM +0200, Johan Hovold wrote: > > > > I just verified break signalling on the first port of my CP2105 using a > > > logic analyser and everything seems to work as expected. > > > > > > There's also no mention of any issue with break in the errata. > > > > > > Could you check which firmware revision you have by enabling debugging > > > and reconnecting the device? > > > [ 4.253869] usb 2-1.2: new full-speed USB device number 3 using ehci-pci > > [ 4.342570] usb 2-1.2: New USB device found, idVendor=10c4, idProduct=ea70, bcdDevice= 1.00 > > [ 4.350939] usb 2-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=5 > > [ 4.358259] usb 2-1.2: Product: CP2105 Dual USB to UART Bridge Controller > > [ 4.365052] usb 2-1.2: Manufacturer: Silicon Labs > > [ 4.369765] usb 2-1.2: SerialNumber: 01070456 > > [ 4.374925] cp210x 2-1.2:1.0: cp210x converter detected > > [ 4.381086] cp210x 2-1.2:1.0: cp210x_get_fw_version - 1.18.1 > > [ 4.386915] usb 2-1.2: cp210x converter now attached to ttyUSB0 > > [ 4.393529] cp210x 2-1.2:1.1: cp210x converter detected > > [ 4.399835] cp210x 2-1.2:1.1: cp210x_get_fw_version - 1.18.1 > > [ 4.405657] usb 2-1.2: cp210x converter now attached to ttyUSB1 > > So we have the same firmware revision. > > > This is an embedded reference board, I guess there is some probability > > that this is just broken on this board, though I'm not quite sure how. > > Is the port accessible somehow so that you could hook up a scope or > logic analyser? Or is that what you did already when you mentioned > seeing garbage sent after 2.5 seconds? I didn't hook up a scope, but I did set the baud to a really low rate and send a character that was all zeros and got a break on the other end. It wasn't garbage I was seeing after 2.5 seconds, it was basically a small number of 0 bits, it appeared. I have a scope that I can capture with, but this is all embedded onto a board. I looked at the schematic and there are some resistors that I could hook to, perhaps. I'll see what I can do, but I don't have surface mount stuff to be able to attach easily. Thank you, -corey > > That last bit seems to match the behaviour I see with the second, SCI > port, where the last character sent is resent when trying to signal a > break. > > Johan
