[PATCH] Powerpc 8xx CPM_UART delay in receive

Alan Cox alan at lxorguk.ukuu.org.uk
Fri Aug 17 00:29:18 EST 2012


> The PowerPC CPM is working differently. It doesn't use a fifo but 
> buffers. Buffers are handed to the microprocessor only when they are 
> full or after a timeout period which is adjustable. In the driver, the 

Which is different how - remembering we empty the FIFO on an IRQ

> buffers are configured with a size of 32 bytes. And the timeout is set 
> to the size of the buffer. That is this timeout that I'm reducing to 1 
> byte in my proposed patch. I can't see what it would break for high 
> speed I/O.

How can a timeout be measured in "bytes". Can we have a bit more clarity
on how the hardware works and take it from there ?

Alan


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