[U-Boot] [PATCH v4 2/2] NS16550: buffer reads

[Wolfgang Denk]

Dear Graeme Russ,

In message <4EA34086.4030101 at gmail.com> you wrote:
> 
> One problem I see with XON/XOFF is that if we don't send XOFF at the right
> time, we run the risk of entering a busy loop (any reasonable timeout delay
> for example) and loosing input. So in theory, we would need to send XOFF
> after every getc() ...

That's not true.  I am not aware of any significant delays that take
place while receiving characters that belong to a single line.  If we
had any of these, we would lose characters all the time - but we
don't.

It should be sufficient to send XOFF after receiving a newline
character.

> Maybe we need disable/enable flow control functions for when we know we
> will be entering a busy loop the consumes serial input (ymodem and kermit
> transfers and readline for example)

This should not be necessary. Actually the implementation should not
need to know about such special cases.

Best regards,

Wolfgang Denk

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