Hi Fabio, Thanks for the response...
On Wed, Apr 29, 2015 at 10:24 AM, Fabio Estevam <[email protected]> wrote: > Hi Will, > > On Wed, Apr 29, 2015 at 9:08 AM, Frazer, Will <[email protected]> > wrote: > >> In tests I can see that with the value set as 1, under intensive >> serial use, CPU use goes towards about 20% (solo core). With the >> value set to 14 it’s closer to 2%. > > I think your proposal makes sense. > > Should we also change TXTL? Probably. Not looked too closely at what a sensible value should be. For now, I'm only interested in RX data. Open to suggestions ;-) >I tested your proposal and it seems we need some logic to adjust the RXTL >value. > >For console operation we need it to be RXTL, otherwise we miss echoing the >chars. Yes. We added a check to see if it was a console for our test - leaving it set to 1 for a console tty. >Have you tried using DMA? Not explicitly - just used opened it as standard serial device. I assumed any DMA logic in the driver would take care of this if needed. If it doesn't, I presume it's still an issue right? Or are you saying that this needs testing separately? I guess this is kinda where I'm coming from... is there a known reason why it is the way it is? I ought to add that I'm testing on an old kernel (3.0.35) so driver operation may differ w.r.t DMA. The RXTL=1 setting has been around for a while but maybe other things work slightly differently. Code looks v.similar at an overview level. regards, Will -- _______________________________________________ meta-freescale mailing list [email protected] https://lists.yoctoproject.org/listinfo/meta-freescale
