On Tue, 14 Jul 2020 15:58:53 +0000 Westergreen, Dalon wrote: > On Tue, 2020-07-14 at 08:55 -0700, Jakub Kicinski wrote: > > On Tue, 14 Jul 2020 14:35:16 +0000 Ooi, Joyce wrote: > > > > I'm no device tree expert but these look like config options rather than > > > > HW > > > > description. They also don't appear to be documented in the next patch. > > > > > > > > > > The poll_freq are part of the msgdma prefetcher IP, whereby it > > > specifies the frequency of descriptor polling operation. I can add > > > the poll_freq description in the next patch. > > > > Is the value decided at the time of synthesis or can the driver choose > > the value it wants? > > It is not controlled at synthesis, this parameter should likely not be a > devicetree parameter, perhaps just make it a module parameter with a default > value.
Let's see if I understand the feature - instead of using a doorbell the HW periodically checks the contents of the next-to-use descriptor to see if it contains a valid tx frame or rx buffer? I've seen vendors abuse fields of ethtool --coalesce to configure similar settings. tx-usecs-irq and rx-usecs-irq, I think. Since this part of ethtool API has been ported to netlink, could we perhaps add a new field to ethtool --coalesce?
