Messages in this thread | | | Date | Fri, 26 Aug 2022 13:37:37 +0200 | From | Michael Walle <> | Subject | Re: [PATCH] Revert "reset: microchip-sparx5: allow building as a module" |
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Hi,
Am 2022-07-13 14:08, schrieb Philipp Zabel: > On Mi, 2022-07-13 at 11:52 +0200, Michael Walle wrote: >> [+ Horatiu, I missed you earlier, sorry] >> >> Hi Steen, >> >> Am 2022-07-13 11:40, schrieb Steen Hegelund: >> > I am afraid that the exact list of affected modules is not available, >> > so using the >> > RESET_PROT_STAT.SYS_RST_PROT_VCORE bit is the best known way of >> > resetting as much as possible, and >> > still continue execution. >> >> Mh, you are designing that chip (at least the LAN966x) no? Shouldn't >> that information be available anywhere at Microchip? ;) >> >> Anyway, it looks like almost the whole chip is reset >> except some minor things. So the driver has actually a >> wrong name. Until recently only the switch driver was the >> sole user of it (at least on the lan966x). So, my question >> remains, is this correct? I mean the switch driver says, >> "reset the switch core", but what actually happens is that >> the the entire SoC except the CPU and maybe the io mux is reset. >> What about the watchdog for example? Will that be reset, too? > > If [1-3] are to be trusted, RESET_PROT_STAT[VCORE_RST_PROT_WDT], which > protects the watchdog from soft reset, is not set by default. So yes? > > There are also AMBA, PCIe, PDBG protection bits against Vcore soft > reset in this register, depending on the platform.
*But* this also prevents it from reset by the watchdog. I don't know if we want that?!
I.e. what happens if one sets RESET_PROT_STAT[VCORE_RST_PROT_WDT] and the watchdog does a reset? OTHO, I guess it is also bad to reset the watchdog during boot.. IMHO this reset logic doesn't look that well designed.
> [1] > https://microchip-ung.github.io/sparx-5_reginfo/reginfo_sparx-5.html?select=cpu,cpu_regs,reset_prot_stat > [2] > https://microchip-ung.github.io/lan9662_reginfo/reginfo_LAN9662.html?select=cpu,cpu_regs,reset_prot_stat > [3] > https://microchip-ung.github.io/lan9668_reginfo/reginfo_LAN9668.html?select=cpu,cpu_regs,reset_prot_stat
-michael
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