Marc Gonzalez <marc_gonza...@sigmadesigns.com> writes: > On 14/11/2017 13:40, Måns Rullgård wrote: > >> Marc Gonzalez wrote: >> >>> Power entire ethernet block down in ndo_stop(). >>> Power it back up in ndo_open() and perform HW init. >>> Delete nb8800_dma_stop. >> >> Leave it alone, please. Not all chips might have a separate power >> domain for this. Also, it works just fine on the older chips. > > There is no need for separate power domains. The ethernet block is > clock-gated when it is held in reset.
So you're not powering it down then. Please be accurate. > The reset register is implemented on all tango3, tango4, tango5 chips. It's still not a core feature. > nb8800_dma_stop() is a hack. The hack originated from your company. > The HW dev has stated that it is not supported. One cannot conclude > that it "works fine" just because you've never triggered the error > condition. (On tango5, the error condition triggers systematically.) That sounds like a problem for tango5. Also, I have repeated asked you what happens if the tango5 runs out of DMA buffers under normal operation. Does that also cause it to lock up? If so, you have a much bigger problem on your hands. > We have several customer bug reports on tango3 and tango4 chips complaining > about "broken" ethernet after a link down / link up cycle. They are using a > different driver, but it implements the same hack in enet_stop_rx(). > There is a high probability that the DMA hack is responsible, and wedged the > RX DMA state machine. But you have no idea what's really the problem? -- Måns Rullgård
