Messages in this thread | | | Date | Wed, 13 Mar 2024 17:38:35 +0200 | From | Justin Swartz <> | Subject | Re: [PATCH] net: dsa: mt7530: increase reset hold time |
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On 2024-03-13 17:04, Arınç ÜNAL wrote: > On 13.03.2024 16:13, Justin Swartz wrote: >> On 2024-03-13 14:06, Arınç ÜNAL wrote: >>> On 13.03.2024 14:52, Justin Swartz wrote: >>>> >>>> On 2024-03-13 10:59, Arınç ÜNAL wrote: >>>>> This ship has sailed anyway. Now the changes the first patch did >>>>> must be >>>>> reverted too. I will deal with this from now on, you can stop >>>>> sending >>>>> patches regarding this. >>>> >>>> At least if the first patch isn't reverted, the approach used is >>>> less likely to result in the problem occuring, IMHO. >>> >>> I disagree that the previous approach is less likely to result in the >>> problem occurring. If you don't like the delay amount we agreed on, >>> feel >>> free to express a higher amount. >> >> I created and tested a patch to entertain your input about what you >> thought could be a suitable hold period to address the problem, and it >> appeared to work. The criteria being that the crystal frequency >> selection >> was correct over 20 tests. >> >> So if only the reset hold period is going to change, I'm good with >> what >> you had suggested: 5000 - 5100 usec. >> >> Ultimately the selection of this period should be guided by the timing >> information provided in a datasheet or design guide from the >> manufacturer. > > That's a good point, I agree. > >> >> If you, or anyone else, has such a document that provides this >> information >> and is able to confirm or deny speculation about any/all timing >> periods >> related to reset, please do so. > > These are the documents I use to program this switch family. I did not > stumble upon a page going over this. > > MT7621 Giga Switch Programming Guide v0.3: > > https://github.com/vschagen/documents/blob/main/MT7621_ProgrammingGuide_GSW_v0_3.pdf > > MT7531 switch chip datasheet: > > https://wiki.banana-pi.org/Banana_Pi_BPI-R64#Documents
Thanks for the links.
Have you encountered this one?
MT7530 Giga Switch Programming Guide v0.1: https://github.com/libc0607/arduino_mt7530/blob/master/MT7530_programming_guide_V00.pdf
It has some timing diagrams, but nothing I found for reset.
The HWTRAP description has some bits swapped, so I guess those were typos, in the case of XTAL_SELECT.
>>> I also disagree on introducing a solution that is in addition to >>> another >>> solution, both of which fix the same problem. >> >> I'm not sure I understand why you say that. These patches were >> intended >> to be applied exclusively, or in other words: in isolation - not >> together. >> >> Although if they were applied together, it wouldn't really matter. >> >> For the record, I've only continued to keep this thread alive in the >> hope that some solution to this problem will make it into mainline >> eventually. >> >> I don't care if it was my original patch, the subsequent patch, or a >> later patch provided by you or someone else. :) > > I think you've missed that your patch is already applied. And it won't > be > reverted for reasons explained by Paolo in this mail thread. > > https://git.kernel.org/netdev/net-next/c/2920dd92b980 > > So if your patch here were to be applied too, the final mt7530.c would > have > the LEDs disabled AND before reset deassertion delay increased.
Yes, I seem to have missed that. I thought your request for the patch to be reverted definitely would have been performed, or at least queued, seeing as you're the maintainer.
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