On Mon, Dec 19, 2016 at 2:58 AM, Johan Hovold <johan@xxxxxxxxxx> wrote:
> On Sat, Dec 17, 2016 at 03:27:43AM -0800, Russell Senior wrote:
>> All testing is with minicom.
>
> Thanks for this through report.
>
>> Starting with 00013-gc510871:
>>
>> In 8-bit mode, interoperates correctly with pl2303. Switching to
>> 5-bit mode on both sides (I get unicode boxes of indeterminate
>> values). Switching back to 8-bit mode on both sides, I get correct
>> text out both sides. Switching just the ch341 side back to 5-bit
>> mode, I get 0xff's out on the pl2303 side (still in 8-bit mode). This
>> would seem to imply that byte-size changes are working on this
>> version. Changing baud rate also works.
>
> Can you verify also what comes through in 5-bit mode is indeed what's
> expected (e.g. 'a' -> 0x01, 'b' -> 0x02, ...)?
>
> You can enable usb-serial debugging to get a log of what is received:
>
> modprobe usbserial dyndbg==p
>
Yes, it does seem that I'm getting the 5-bit truncation. Here is an
excerpt from the prodigious logs, in this case sending a 'Z' from
pl2303 and receiving an 0x5a on the ch341. The same sort of thing,
e.g. 'A' (0x41) from the ch341 lands as an 0x01 on the pl2303, 0x42 ->
0x02, etc.
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_chars_in_buffer
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_chars_in_buffer - returns 0
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_write_room
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_write_room - returns 4096
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_tiocmget
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_ioctl - cmd 0x5401
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_chars_in_buffer
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_chars_in_buffer - returns 0
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_write_room
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_write_room - returns 4096
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_chars_in_buffer
Dec 19 08:22:53 willard kernel: pl2303 ttyUSB1:
usb_serial_generic_chars_in_buffer - returns 0
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_write_room
Dec 19 08:22:53 willard kernel: pl2303 ttyUSB1:
usb_serial_generic_write_room - returns 4096
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_tiocmget
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_ioctl - cmd 0x5401
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_chars_in_buffer
Dec 19 08:22:53 willard kernel: pl2303 ttyUSB1:
usb_serial_generic_chars_in_buffer - returns 0
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_write_room
Dec 19 08:22:53 willard kernel: pl2303 ttyUSB1:
usb_serial_generic_write_room - returns 4096
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_chars_in_buffer
Dec 19 08:22:53 willard kernel: pl2303 ttyUSB1:
usb_serial_generic_chars_in_buffer - returns 0
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_write_room
Dec 19 08:22:53 willard kernel: pl2303 ttyUSB1:
usb_serial_generic_write_room - returns 4096
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_write - 1 byte(s)
Dec 19 08:22:53 willard kernel: pl2303 ttyUSB1:
usb_serial_generic_write_start - length = 1, data = 5a
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_tiocmget
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_ioctl - cmd 0x5401
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_chars_in_buffer
Dec 19 08:22:53 willard kernel: pl2303 ttyUSB1:
usb_serial_generic_chars_in_buffer - returns 1
Dec 19 08:22:53 willard kernel: tty ttyUSB1: serial_write_room
Dec 19 08:22:53 willard kernel: pl2303 ttyUSB1:
usb_serial_generic_write_room - returns 4096
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_read_bulk_callback - urb 1, len 1
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_read_bulk_callback - length = 1, data = 1a
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_submit_read_urb - urb 1
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_chars_in_buffer
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_chars_in_buffer - returns 0
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_write_room
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_write_room - returns 4096
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_tiocmget
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_ioctl - cmd 0x5401
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_chars_in_buffer
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_chars_in_buffer - returns 0
Dec 19 08:22:53 willard kernel: tty ttyUSB0: serial_write_room
Dec 19 08:22:53 willard kernel: ch341-uart ttyUSB0:
usb_serial_generic_write_room - returns 4096
>> 00014-g79e475a:
>>
>> dmesg shows on insert:
>>
>> [ 1430.504116] usb 6-2: new full-speed USB device number 3 using uhci_hcd
>> [ 1430.682143] usb 6-2: New USB device found, idVendor=1a86, idProduct=7523
>> [ 1430.682148] usb 6-2: New USB device strings: Mfr=0, Product=2, SerialNumber=0
>> [ 1430.682152] usb 6-2: Product: USB2.0-Ser!
>> [ 1430.686294] ch341 6-2:1.0: ch341-uart converter detected
>> [ 1430.689122] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (pre version)
>> [ 1430.693121] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post init-0)
>> [ 1430.693124] usb 6-2: ch341_set_baudrate_lcr - speed = 9600, lcr =
>> c3, a = b202
>> [ 1430.696120] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post divisor)
>> [ 1430.699119] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post lcr)
>> [ 1430.700501] usb 6-2: ch341-uart converter now attached to ttyUSB0
>>
>> Changing baud rate and then byte-size:
>>
>> [ 1621.189700] usb 6-2: ch341_set_baudrate_lcr - speed = 9600, lcr =
>> c3, a = b202
>> [ 1621.193556] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post divisor)
>> [ 1621.196557] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post lcr)
>> [ 1621.199565] usb 6-2: ch341_set_baudrate_lcr - speed = 115200, lcr =
>> c3, a = cc03
>> [ 1621.202571] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post divisor)
>> [ 1621.205569] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post lcr)
>> [ 1621.207572] usb 6-2: ch341_set_baudrate_lcr - speed = 115200, lcr =
>> c3, a = cc03
>> [ 1621.210570] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post divisor)
>> [ 1621.213573] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post lcr)
>> [ 1644.117396] usb 6-2: ch341_set_baudrate_lcr - speed = 9600, lcr =
>> c3, a = b202
>> [ 1644.120933] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post divisor)
>> [ 1644.123952] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post lcr)
>> [ 1666.950341] usb 6-2: ch341_set_baudrate_lcr - speed = 9600, lcr =
>> c0, a = b202
>> [ 1666.954320] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post divisor)
>> [ 1666.957316] usb 6-2: ch341_dbg - [0x2518] = c0 00, [0x1213] = 00 00
>> (post lcr)
>> [ 1700.500318] usb 6-2: ch341_set_baudrate_lcr - speed = 9600, lcr =
>> c3, a = b202
>> [ 1700.503845] usb 6-2: ch341_dbg - [0x2518] = c0 00, [0x1213] = 00 00
>> (post divisor)
>> [ 1700.506866] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post lcr)
>>
>> It works in 8-bit mode, I can change to 5-bit mode and then back, as
>> before. And I can change baud rate.
>
> Note that you only need to test this commit, which simply adds the
> debugging printks on top of the previous.
>
> The log indicates that the LCR is updated correctly, but also reveals
> that the divisor registers always read back as zero even if changing
> speeds appear to work. Both my devices read back the values set either
> through direct register write or using the init commmand.
>
> We may be able to use this to detect these devices and fall back to
> direct register writes.
>
>> 00015-gee5a27b:
>
>> I can switch baud rate and byte size back and forth and it seems to
>> work. In 5-bit mode, I guess minicom just doesn't know how to render
>> the values, so that makes sense, switching back to 8-bit mode and I
>> get readable text again. So, this one is working too, afaict.
>
> Good, this one only differs from the previous in that the 7th bit of the
> divisor register is set, something which is required for CH341A. Good to
> know it does not seem to have any negative effects for this device.
>
>> 00016-ga06b45d:
>>
>> dmesg on insert:
>>
>> [ 2588.016052] usb 6-2: new full-speed USB device number 5 using uhci_hcd
>> [ 2588.189182] usb 6-2: New USB device found, idVendor=1a86, idProduct=7523
>> [ 2588.189187] usb 6-2: New USB device strings: Mfr=0, Product=2, SerialNumber=0
>> [ 2588.189192] usb 6-2: Product: USB2.0-Ser!
>> [ 2588.193366] ch341 6-2:1.0: ch341-uart converter detected
>> [ 2588.196146] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (pre version)
>> [ 2588.200162] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post init-0)
>> [ 2588.200165] usb 6-2: ch341_set_baudrate_lcr - speed = 9600, lcr =
>> c3, a = b202
>> [ 2588.203182] usb 6-2: ch341_dbg - [0x2518] = c3 00, [0x1213] = 00 00
>> (post init)
>> [ 2588.204488] usb 6-2: ch341-uart converter now attached to ttyUSB0
>>
>> This doesn't work. Even when matching baud rate and byte size, the
>> best I get is 0xff's out on the ch341. Nothing decodes as printable
>> anything at the pl2303 side.
>
> Ok, so the init command cannot be used to switch baud rate for these
> devices.
>
> Could you see if you can communicate using 19200 baud (when using this
> or the next commit), which is the default baud rate for the devices I
> have (i.e. default settings are 19200 8N1).
19200 8N1 on this commit does not work.
>
>> 00017-g6edc283:
>
>> This doesn't work either. At 9600 8N1, I get 0xff's on the pl2303,
>> and some unicode on the ch341.
>
> If the baud rate cannot be set using the init command, then this should
> behave as the previous commit. 19200 baud might work.
>
>> Let me know if I can test anything else!
>
> Apart from the two additional tests mentioned above, can you also
> provide a log from when connecting the device using the following commit
> that I just pushed to the ch341 branch:
>
> f341ee36198d ("dbg: ch341: add register dumps to probe")
>
> which provides dumps of the register settings during initialisation.
> (Make sure ch341 dynamic debugging is not enabled to avoid cluttering
> the log.)
I'll send this in a followup, need to rebuild.
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