Issue with Qotom Q190P IT8768 Serial Chip

CraftyMyner · 09-24-2017, 02:40 AM

Hello everyone,

I seem to be having an issue with my Qotom Q190P embedded computer's back 3 serial ports.

The single front serial port uses an IT8758 Super IO driver chip and works perfectly, however, I am unable to send or receive any data on the back 3 ports.

I have tried quite a few solutions with no success. The ports show up with addresses, UARTs and IRQs under "/proc/tty/driver/serial", however, when attempting to use a multitude of different programs to send or receive data nothing works.

I have been looking around and it appears that linux supports the IT8758 chip used for the front port but doesn't support the IT8768 chip use for the back ones. Is anyone able to point me in a direction to solving this issue or let me know if there is no support for the IT8768 chip?

Greatly appreciated,
Alex

business_kid · 09-24-2017, 02:32 PM

Does it have 4 serial ports? From http://www.qotom.net/goods-128-QOTOM...l+mini+PC.html

Code:

Front-Panel Connectors
	
• 1 x Power switch button ( Power LED )
• 1 x HDD LED
• 3 x USB2.0 ports
• 1 x USB3.0 ports
• 1 x Microphone port
• 1 x Serial port (RS232)
Back-Panel Connectors
	
• 1 x 12V DC input
• 1 x HD Video port
• 1 x VGA port 
• 2 x RJ-45 port 
• 3 x Speaker port

I don't see any 'back 3 serial ports.I think they're counting 2xusb-2.0 and 1xusb-3.0 ports as 'com' ports as well as the single com port.

If the chip is programmable, parts can be reconfigured or disabled. One serial port is a concession to antiquity these days. I don't know if modern OSes handle more than 2. You might be better employed looking at usb-serial options if you have to use technology from the last millenium.

Go at it Methodically. What shows in a boot?

Code:

dmesg |grep -i serial

CraftyMyner · 09-24-2017, 03:49 PM

Hello,

I am using this computer: http://www.qotom.net/goods-128-QOTOM...l+mini+PC.html

Code:

Front-Panel Connectors
• 1 x Power switch button ( Power LED )
• 1 x HDD LED
• 3 x USB2.0 ports
• 1 x USB3.0 ports
• 1 x Microphone port
• 1 x Serial port (RS232)
Back-Panel Connectors
• 1 x 12V DC input
• 1 x HD Video port
• 1 x VGA port 
• 2 x RJ-45 port 
• 3 x Speaker port

My results from:

Code:

dmesg |grep -i serial

are:

Code:

[    1.487630] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
[    1.584841] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    1.584847] usb usb1: SerialNumber: 0000:00:14.0
[    1.586308] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    1.586314] usb usb2: SerialNumber: 0000:00:14.0
[    2.063009] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    2.063016] usb 1-2: SerialNumber: AARK5H31ISSS6E4Z
[    2.322385] usb 1-4: New USB device strings: Mfr=0, Product=1, SerialNumber=0
[    2.714684] usb 1-4.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    2.714690] usb 1-4.3: SerialNumber: 00000000000097
[    2.905170] usb 1-4.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0

My results from:

Code:

dmesg |grep -i ttyS

are:

Code:

[    1.508295] 00:03: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[    1.529121] 00:05: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A
[    1.549942] 00:06: ttyS2 at I/O 0x3e8 (irq = 10, base_baud = 115200) is a 16550A
[    1.570763] 00:07: ttyS3 at I/O 0x2e8 (irq = 11, base_baud = 115200) is a 16550A

Thanks

business_kid · 09-25-2017, 04:18 PM

The picture definitely shows 4 com ports, although the listing of parts does not. But if you say you have 4 com ports, I'll shut up and take your word for it.

Going on the photo, it seems like 4 com ports. Could you post the output of this command inserting numbers increasing from zero by 1 until 4

Code:

setserial /dev/ttyS0

That's ttyS0, ttyS1, etc.

CraftyMyner · 09-25-2017, 06:05 PM

I think they miss labeled "Serial Port" to "Speaker Port", the name of the computer is "Q190P with 4 COM Ports".

Output:

Code:

/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
/dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 3
/dev/ttyS2, UART: 16550A, Port: 0x03e8, IRQ: 10
/dev/ttyS3, UART: 16550A, Port: 0x0238, IRQ: 11

Thanks again

masosi · 10-28-2017, 03:54 AM

I have the same PC with the same problem and have not been able to find a solution.

Please let me know if anyone has had any luck with this - kind if pointless having 4 serial ports if only 1 is supported.

Thanks

masosi

business_kid · 10-29-2017, 06:37 AM

Quote:

Originally Posted by CraftyMyner

I think they miss labeled "Serial Port" to "Speaker Port", the name of the computer is "Q190P with 4 COM Ports".

Output:

Code:

/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
/dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 3
/dev/ttyS2, UART: 16550A, Port: 0x03e8, IRQ: 10
/dev/ttyS3, UART: 16550A, Port: 0x0238, IRQ: 11

Thanks again

16550A is definitely serial port hardware, so these are serial port chips, probably occupying some few per cent of a vast integrated Southbridge ASIC. The Northbridge/Southbridge design has been outmoded by further integration, notably APUs (including cache) replacing discrete cpu, gpu, & cache, but there will be a bit that resembles the Southbridge, talking to the APU and all the I/O. You guys need to get onto the manufacturer, find the full chip name complete with prefixes, numbers, & suffixes) ideally of that device, or install the manufacturer's OS and see if that works the 4 ports. I smell a non 100% compatible piece of hardware. As well, query the situation if the address space (0x2f8, 0x3e8 & 0x238) can still be used as I/O with whatever distro you're using. Each of those locations uses 8 bits for the I/O, e.g. 0x2f8 - 0x2ff. That hardware is NOT modern. It's a while since I heard of Celerons.

masosi · 10-29-2017, 06:51 AM

Quote:

Originally Posted by business_kid

16550A is definitely serial port hardware, so these are serial port chips, probably occupying some few per cent of a vast integrated Southbridge ASIC. The Northbridge/Southbridge design has been outmoded by further integration, notably APUs (including cache) replacing discrete cpu, gpu, & cache, but there will be a bit that resembles the Southbridge, talking to the APU and all the I/O. You guys need to get onto the manufacturer, find the full chip name complete with prefixes, numbers, & suffixes) ideally of that device, or install the manufacturer's OS and see if that works the 4 ports. I smell a non 100% compatible piece of hardware. As well, query the situation if the address space (0x2f8, 0x3e8 & 0x238) can still be used as I/O with whatever distro you're using. Each of those locations uses 8 bits for the I/O, e.g. 0x2f8 - 0x2ff. That hardware is NOT modern. It's a while since I heard of Celerons.

Thanks business_kid,

The BIOS has the 3 problematic serial ports as configurable adresses and irqs, which match what ubuntu is seeing - so I guess they are real. Unless the BIOS addresses are wrong and Ubuntu doesn't know any better?

The problem I have is with Node-Red, when it tries to CLOSE the serial port, it times-out after 15secs. Yet it seems to open the port without any errors. Strange.

I have contacted the manufacturer a day or two ago (before the weekend), so will wait for their reply and ask those questions you've suggested.

Thanks for your help,
masosi.

business_kid · 10-29-2017, 06:07 PM

Quote:

The BIOS has the 3 problematic serial ports as configurable adresses and irqs, which match what ubuntu is seeing - so I guess they are real. Unless the BIOS addresses are wrong and Ubuntu doesn't know any better?

The only one that looks odd to me is 0x238. I was expecting 0x2e8. But then it's been a long time. The others are spot on, i.e standard (dos) I/O which was adopted by linux because they wanted things to work.

masosi · 10-31-2017, 12:35 AM

Quote:

Originally Posted by business_kid

The only one that looks odd to me is 0x238. I was expecting 0x2e8. But then it's been a long time. The others are spot on, i.e standard (dos) I/O which was adopted by linux because they wanted things to work.

I just re-checked mine and it is in fact 0x2e8 like you were expecting. The others are the same.

I just received a reply from the supplier/manufacturer they said the Transceiver is EXAR SP213E. I understand this is the actual hardware output driver chip, but how does this relate to the Intel IT8768 that the BIOS is reporting?

Thanks,
masosi.

business_kid · 11-01-2017, 08:07 AM

Just went back to the datasheets for you. Old habits die hard. The Exar SP213E is in fact a 4 serial port chip, complete with charge pumps to provide the odd voltages that RS232 ports require.

The IT8768, is very poorly documented and AFAICT. Unless you know better, You decode an IC number this way:

LLL:NNNNN:<suffix> which is Manufacturer: base chip number: variant specifying extra features. I would expect an intel 8768 to be i8768, not IT. IT to me, looks more like ITE, some fab-less chip design house in the far east. If Intel ever made an 8768, it was back in the through hole 1980s and obsoleted decades ago. There may be a just-in-case serial port thrown into the Southbridge, but I woul;dn't expect it because of the voltages required.

@ masosi & CraftyMyner
Search your boards both of you, for the EXAR SP213E and the IT8768. If you can't find one, try tracing your serial ports back to whatever they go to. That's very difficult, but you may get a general idea where they're headed. Get a chip manufacturer for the IT8768 if you find one. Get your exact motherboard number. Go through the bios and make doubly sure all ports are enabled. Then take this up with your supplier. From what I can tell the IT8768 and Exar SP213E are not compatible.

business_kid · 11-01-2017, 12:07 PM

An idea uncurled itself in my brain and I did one more search. The chips in that number range beginning with IT belong to ITE Electronics, but may be part of an ASIC. (explanation below). The IT 8728 & the IT8772 are ENVIRONMENT CONTROLLERS. It is likely that intervening numbers are also. An environment controller may have several serial ports to talk to sensors. That would fit nicely if no serial port worked, except one does.

/Begin boring explanation
You are familiar with Arm processors in mobile devices, but most are just designs in Verilog, VHDL, or some hardware format that get loaded into an ASIC design. I haven't worked with ASICs (Application Specific Integrated Circuits) which are fabricated in Silicon, but I have worked with FPGAs which are much like Eproms - they come blank, and you program them. The idea is basically the same: You start, say a vhdl project and it has a directory for it's .vhd files. Simply copy in prebought designs, and it looks at this directory, programs in all the dirty thoughts in your file collection, and programs your device.

masosi · 11-01-2017, 04:33 PM

Quote:

Originally Posted by business_kid

Just went back to the datasheets for you. Old habits die hard. The Exar SP213E is in fact a 4 serial port chip, complete with charge pumps to provide the odd voltages that RS232 ports require.

The IT8768, is very poorly documented and AFAICT. Unless you know better, You decode an IC number this way:

LLL:NNNNN:<suffix> which is Manufacturer: base chip number: variant specifying extra features. I would expect an intel 8768 to be i8768, not IT. IT to me, looks more like ITE, some fab-less chip design house in the far east. If Intel ever made an 8768, it was back in the through hole 1980s and obsoleted decades ago. There may be a just-in-case serial port thrown into the Southbridge, but I woul;dn't expect it because of the voltages required.

@ masosi & CraftyMyner
Search your boards both of you, for the EXAR SP213E and the IT8768. If you can't find one, try tracing your serial ports back to whatever they go to. That's very difficult, but you may get a general idea where they're headed. Get a chip manufacturer for the IT8768 if you find one. Get your exact motherboard number. Go through the bios and make doubly sure all ports are enabled. Then take this up with your supplier. From what I can tell the IT8768 and Exar SP213E are not compatible.

Thank you for the valuable information. I will continue to track down a solution with the manufacturer, who are telling me the serial ports work ok with Windows. I am waiting for them to reply if they have had them working with Linux yet.

The other option is a hardware failure, which I will have to install Windows to test them that way - but two people having the same hardware fault seems kind of unlikely in this case.

Thank you again business_kid.
masosi.

business_kid · 11-02-2017, 04:45 AM

Just one more thing. If you're suspicious of any chip, post a clear camera shot of it, and I can recognise a lot of stuff you mightn't.

masosi · 11-04-2017, 03:25 AM

Alright!

I have found a solution (some may disagree).
If I set the IRQs of the 3 serial ports to zero, everything seems to work fine. I understand setserial IRQ 0 means the port will be polled for data instead of using hardware interrupts, but that's the only way I can get this to work.

Code:

Add this to:
sudo nano /etc/rc.local

# Set serial ports 1, 2 and 3 to not use IRQs and just poll instead:
sudo /bin/setserial /dev/ttyS1 baud_base 115200 closing_wait 20 irq 0 skip_test autoconfig
sudo /bin/setserial /dev/ttyS2 baud_base 115200 closing_wait 20 irq 0 skip_test autoconfig
sudo /bin/setserial /dev/ttyS3 baud_base 115200 closing_wait 20 irq 0 skip_test autoconfig

I've tried a few different combinations of IRQs but haven't had much luck and gave up after a few tries. I've had the BIOS on auto, specified IRQ, and a range of IRQs. Nothing seems to be working for me when I use IRQs.

I hope this helps someone. Maybe there is a better way, but this will do for me for now.

Thanks again business_kid.

masosi.