lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 6 Oct 2021 13:35:35 +0200 From: Alexandre Ghiti <alexandre.ghiti@...onical.com> To: Adam Thomson <Adam.Thomson.Opensource@...semi.com> Cc: David Abdurachmanov <david.abdurachmanov@...il.com>, Support Opensource <Support.Opensource@...semi.com>, Lee Jones <lee.jones@...aro.org>, "linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org> Subject: Re: [PATCH] drivers: mfd: da9063: Add restart notifier implementation On Wed, Oct 6, 2021 at 11:30 AM Adam Thomson <Adam.Thomson.Opensource@...semi.com> wrote: > > On 05 October 2021 14:43, Alexandre Ghiti wrote: > > > > > > Thanks for the pointer! I have just tested this sequence from the > > > > > u-boot shell, it resets the board correctly. But then if we try to > > > > > power down the board by a long press to the corresponding button on > > > > > the board within 16 seconds, it resets the board: so we cannot > > > > > shutdown the board in the next 16 seconds that follow this sequence. > > > > > > > > > > Maybe that can be resolved by using the one-shot alarm as described by > > > > > Adam, I'll try to find that in the datasheet. > > > > > > > > After configuring the one-shot alarm, I still have those intempestive > > > > reboots if I try to power down the board by a long press within 16 > > > > seconds. The only thing I found in the datasheet regarding this timing > > > > is in case of power undervoltage, not sure how this is linked to what > > > > I see. > > > > > > > > @Adam Thomson Any ideas? > > > > > > Nothing immediately springs to mind. Can you confirm this is the nONKEY long > > > press that you're attempting here, which is resetting the board rather than > > > shutting down? > > > > Yes, this is the nONKEY long press that, if done within ~16sec after > > the board is reset using the alarm, resets the board instead of > > shutting it down. > > > > > > > > Also, would you able to again provide events and fault log when this unwanted > > > reset occurs, just in case there's anything there to give a clue. Can then > > > discuss internally to see if we can ascertain what might be happening here. > > > > FAULT_LOG = 0x60 > > EVENT_A = 0x12 > > EVENT_B to EVENT_D = 0 > > > > But I'm unsure of those values since they are the same after the reset > > triggered by the one-shot alarm *and* if I clear EVENT_A, the > > intempestive reboot does not appear! > > Thanks for the info. So we believe, based on the event registers values > provided, it is the RTC event as that's not cleared by a power-cycle (it's in > the always-on domain). The other test would be to mask this event immediately > after an RTC based reboot and see if the long key-press then shuts down the > device. I suspect it would in that case, as per you clearing the event. Indeed if I mask the RTC alarm in IRQ_MASK_A, the intempestive reboot disappears. But that's not something we can do: the reset driver will actually be implemented in openSBI at some point where the devices are probed on-demand (the same applies to u-boot I think), so we cannot clear or mask anything at boot. > > I'm still curious as to the 16 seconds though. Would that be when the kernel > finally starts and masks/clears events (seems quite a long time)? No, the kernel is not up yet. Maybe 16sec is not the right value, I may have been influenced by the discussion here https://www.dialog-semiconductor.com/products/pmics?post_id=10052#tab-support_tab_content. It seems there is some consensus about having this reset driver be a SiFive Unmatched board specific thing: quid of the sequence I propose in this patch then? It does not mess with the RTC registers, it reboots reliably and there's no intempestive reboot: is it dangerous to use? Or do you have another alternative? Thanks, Alex
Powered by blists - more mailing lists