[PATCH 0/4] handle watchdogs during keyed autoboot

[Rasmus Villemoes]

The fix and explanation is in the first patch, which I hope can make
it into v2022.10, it should be rather uncontroversial.

The second patch may make sense on its own, but is not at all urgent
and can be considered a mere suggestion, but it was convenient for
making the following two patches less intrusive.

While I noticed this on my actual hardware, it's not too hard to
verify the problem in sandbox, which is what patches 2-4 are for.

More precisely, I've tested that with this series (and the stuff added
by the first patch temporarily commented out), building
sandbox64_defconfig modified by setting CONFIG_BOOTDELAY=15 and
CONFIG_AUTOBOOT_KEYED=y, doing

  ./u-boot -D

works as always (ordinary simple autoboot, getting a prompt after 15
seconds), while with

  ./u-boot -D --autoboot_keyed

the sandbox gets killed as expected five seconds into the 15 second
countdown. And with the first patch properly applied, this is fixed.

I don't know if this is a good way to test this, or if having that
SIGALRM based watchdog device running always in sandbox can cause
problems for other uses of sandbox. I also won't have time in the near
future for polishing or reworking the test, so consider it mostly
POC.

Regardless, as I wrote above, I do hope the fix itself (1/4) can be
applied soonish.


Rasmus Villemoes (4):
  autoboot: make sure watchdog device(s) are handled with keyed autoboot
  watchdog: introduce a u-boot,autostart property
  sandbox: add SIGALRM-based watchdog device
  sandbox.dtsi: add a sandbox,alarm-wdt instance

 arch/sandbox/cpu/os.c                        | 17 +++++
 arch/sandbox/dts/sandbox.dtsi                |  6 ++
 common/autoboot.c                            |  3 +
 configs/sandbox64_defconfig                  |  2 +
 configs/sandbox_defconfig                    |  2 +
 doc/device-tree-bindings/watchdog/common.txt |  9 ++-
 drivers/watchdog/Kconfig                     |  8 ++
 drivers/watchdog/Makefile                    |  1 +
 drivers/watchdog/sandbox_alarm-wdt.c         | 79 ++++++++++++++++++++
 drivers/watchdog/wdt-uclass.c                | 15 ++--
 include/os.h                                 | 17 +++++
 11 files changed, 149 insertions(+), 10 deletions(-)
 create mode 100644 drivers/watchdog/sandbox_alarm-wdt.c

-- 
2.37.2