Re:Re:Re:Re: set qemu support serial crtscts

[付小明]

Hi， Peter and all developers

     Yes， I need to describe it clearly. 

1、I want make the qemu serial support crtscts

2、Problem: the machine's guest is windows, the machine's host is centos.  The qemu emulation pci-serial.

A printer （model is BTP-2001cp）use the serial to print. The machine connect the printer by serial port.

The data printed by the printer is missing some data.You can see picture 1 is lost some data, picture 2  is normal.Because the printer need hardware flow control.

This is a bug：

the machine's guest is windows, the machine's host is centos.  The qemu emulation pci-serial.

A printer （model is BTP-2001cp）use the serial to print. The machine connect the printer by serial port.

The data printed by the printer is missing some data

because qemu not support serial hardware flow control。

Do you solve this question? I am looking forward to your reply. Thank you very much

At 2021-05-23 16:30:58, "付小明" <fxm16899@163.com> wrote:

Hi,  Peter and all developers

    Do you solve this question? I am looking forward to your reply. Thank you very much

At 2021-04-15 13:38:08, "付小明" <fxm16899@163.com> wrote:

Hi， Peter and all developers

     Yes， I need to describe it clearly. 

1、I want make the qemu serial support crtscts

2、Problem: the machine's guest is windows, the machine's host is centos.  The qemu emulation pci-serial.

A printer （model is BTP-2001cp）use the serial to print. The machine connect the printer by serial port.

The data printed by the printer is missing some data.You can see picture 1 is lost some data, picture 2  is normal.Because the printer need hardware flow control.

I modify /chardev/char-serial.c to support hardware flow control. Then the data printed by the printer is normal.

The CRTSCTS is (not in POSIX) Enable RTS/CTS (hardware) flow control.  

We can acquire some information by  "stty -F /dev/ttyS0 -a ". We can set the CRTSCTS by "stty -F /dev/ttyS0 crtscts"

3、I have some question

1) Does the qemu init all pci-serial port crtscts or raw? For example, I make the qemu configure with 4 pci-serial port.

 -chardev tty,id=charserial0,path=/dev/ttyS0,logfile=/dev/fdset/4,logappend=on -device pci-serial,chardev=charserial0,id=serial0,bus=pci.0,addr=0x17 -add-fd set=5,fd=28 -chardev tty,id=charserial1,path=/dev/ttyS1,logfile=/dev/fdset/5,logappend=on -device pci-serial,chardev=charserial1,id=serial1,bus=pci.0,addr=0x18 -add-fd set=6,fd=29 -chardev tty,id=charserial2,path=/dev/ttyS2,logfile=/dev/fdset/6,logappend=on -device pci-serial,chardev=charserial2,id=serial2,bus=pci.0,addr=0x19 -add-fd set=7,fd=30 -chardev tty,id=charserial3,path=/dev/ttyS3,logfile=/dev/fdset/7,logappend=on -device pci-serial,chardev=charserial3,id=serial3,bus=pci.0,addr=0x1a

2) if some printer not support (hardware) flow control, we make the qemu support (hardware) flow control, have some bad influence?

.

At 2021-04-14 21:24:20, "Peter Maydell" <peter.maydell@linaro.org> wrote:
>On Wed, 14 Apr 2021 at 14:18, 付小明 <fxm16899@163.com> wrote:
>>
>> HI, I have find qemu serial not support crtscts. This result some
>> machine not communication, because this machine need crtscts
>
>Could you provide more detail, please? For a bug report it
>is useful to know:
> * what you were trying to do
> * what happened
> * what you expected to happen
> * full details like the QEMU command line
> * what guest software you were running
>
>Ideally, the report should have everything we need to be
>able to reproduce the problem ourselves.
>
>thanks
>-- PMM