[Qemu-devel] Re: [PATCH] Elo touchpad 10 bytes emulator v2

[Juan Quintela]

Markus Armbruster <address@hidden> wrote:

>>> I have to send a 2x10 bytes package, and it does not fit the the 16
>>> bytes buffer.... Any other suggestion about how to do it?
>>
>> Nope, I am not a 16550A guru at all.  No sure if your change will break
>> anything else or no, that is why I asked.
>
> The 16550 FIFOs are 16 bytes.  The chips with larger FIFOs have
> different model numbers, e.g. 16650 with 32 byte FIFOs.
>
> I can't see how the FIFO length limits your packet size.  Could you
> explain?

Ah, I found it.  Please look at hw/baum.c to see how to handle bigger
packets.  You can't write 10 + 10 bytes into 16 bytes in one go, you
need to wait for the guest to consume some bits before you sent
something more.

see how baum_accept_input()
handle qemu_chr_can_read() output.  Something like that should fix your 
problems.

Later, Juan.