On Wed, 02 Feb 2022 03:54:45 +0900, Peter Maydell wrote: > > On Tue, 1 Feb 2022 at 17:47, Yoshinori Sato <ys...@users.sourceforge.jp> > wrote: > > > > On Tue, 01 Feb 2022 15:48:58 +0900, > > Thomas Huth wrote: > > > > > > On 31/01/2022 10.42, Yoshinori Sato wrote: > > > If you describe it like this, it sounds like you're now emulating a > > > buffer that is not there with real hardware? Is that really what you > > > want here, i.e. wouldn't this hide problems with the real hardware > > > that are mitigated in QEMU with this buffer? > > > > There is no such buffer in the real hardware. > > It's not possible with real hardware, but the chardev backend passes > > data faster than the bitrate. > > There is no problem if the received data is supplied at the timing when > > it can be received, but since it is difficult to match the timing > > accurately, > > we expect that the buffer will absorb the difference in timing. > > If you can't accept receiving more data from the chardev backend, > your serial device model should be returning 0 from can_receive.
If 0 is returned, the character to be received will be dropped. There is no problem if it is an interactive operation, but when connecting to a socket and communicating continuously, data will be lost if the timing does not match. > I don't think we should model a FIFO that doesn't exist in > the real hardware. > > thanks > -- PMM > -- Yosinori Sato
