Hi Alexandre! On Fri, Nov 13, 2020 at 11:03:59AM +0100, Alexandre Belloni wrote: > I think I'm the only one booting recent linux kernels on at91rm9200 and > I'm currently stuck home while the board is at the office. I'll try to > test as soon as possible, which may not be before 2021... At least I'll > know who is the culprit ;)
Oh that's great. I have a SAMG20 based one, which uses slightly different registers and supports a tx ring, so initially I thought that I couldn't test it there. But a friend of mine who wrote the drivers for FreeBSD told me that the original driver still worked for the SAMG20, and I suspect that despite not being mentioned in the datasheet, the more recent chip still supports the old behavior, at least to ease the transistion for their customers. So eventually I'll try it too. In all transparency, I must tell you that I recently noticed an issue when facing intense bidirectional traffic, eventually the chip would report a TX overrun and would stop sending. I finally attributed this to the unmerged changes needed for the MStar chip, which uses two 16 bit I/O accesses instead of a single 32-bit one, and which apparently doesn't like being interrupted between the two when writing to the TAR or TLEN registers. It took me the whole week-end to figure the root cause so now I need to remove all my debugging code, address the issue and test again. If I can't manage to fix this and you can't find a moment to test on your board, I'll propose to revert my patch to stay on the safe side, as I want at least one implementation to be 100% reliable with it. Cheers, Willy
