Re: [RFC][PATCH] TTY flip buffer SMP changes

[Benjamin Herrenschmidt]

On Sat, 2004-10-09 at 01:00, Theodore Ts'o wrote:

> You can have the driver hang on to the sk_buff for several interrupts
> until it decides to push the data to the line displine.  So even if
> the FIFO is small, we only have to allocate/deallocate the skbuff only
> but rarely, unless someone really needs low_latency --- which should
> be but rarely. 

That reminds me... a while ago, I toyed with the idea of having DMA
support in pmac_zilog. The case where it would work well is typically
for things that have a known sized frame. If that information was
provided down to the driver, I could setup the DMA descriptor for
that frame size & have it interrupt me when the frame is complete,
along with a timeout set to the estimated time for receiving such
a frame + X% (I was thinking +20%)

Ben.


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