On 29.03.2019 16:52, Stefan Roese wrote:
> Hi Eugen, > > On 29.03.19 15:40, eugen.hris...@microchip.com wrote: >>> I've noticed that the first ethernet packet after PHY link establishment >>> is not tranferred correctly most of the time on my AT91SAM9G25 board. >>> Here I usually see a timeout of a few seconds, which is quite >>> annoying. >>> >>> Adding a small delay (10ms in this case) after the link establishment >>> helps to solve this problem. With this patch applied, this timeout >>> on the first packet is not seen any more. >> >> Hi Stefan, >> >> I find this a bit odd... maybe someone with a different board having >> this Ethernet controller can confirm or infirm this ? > > I've seen such issues of timeouts with the first ethernet packet > after link negotiation on other platforms / controllers a few > times before in U-Boot. Using a short delay after link-up always > did help here. > > I'm not saying that this is the perfect solution, but its one that > works and removes these timeouts, which really annoy me. > >> Linux driver for macb has a similar issue ? > > Not that I am aware of. There might be some delay in the link > establishment hidden as well. I did not check yet. > >> Adding a delay just for the sake of it might hide another issue that we >> are missing at this point: why exactly transfer fails right away... it >> is likely that we want to send packets but link in fact is not ready ? > > Yes, something like this. I see there is a small udelay below your code, you add a delay 100 times bigger... maybe that small delay is related ? > >> Or any reason why the packet is not correctly transferred? Do you see >> errors on the line or the packet vanishes completely ? >> What kind of packet is this first one ? Does it depend on the packet >> type ? > > I did not check too closely, as this issue was so similar to the > ones I've seen before in U-Boot (see above). It happens upon > "ping" and "tftp" - that's what I did test with. > >> Sorry for maybe asking too many questions. > > No need to be sorry. If this can be solved in another perhaps > cleaner way, I'll gladly use another solution. > >> I have added Nicolas and Claudiu who have more experience with macb on >> at91 boards > > Sure, let's see what others have to say on this. Did someone else > notice these timeouts resulting in quite big delays? > > Thanks, > Stefan _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot