On 04/06/2020 12:59, Corey Minyard wrote:
On Thu, Jun 04, 2020 at 09:15:33AM +0100, Julien Grall wrote:
Hi,
On 04/06/2020 01:15, Corey Minyard wrote:
On Wed, Jun 03, 2020 at 03:31:56PM -0700, Stefano Stabellini wrote:
Touching the watchdog is required to be able to reboot the board.
The implementation is based on
drivers/watchdog/bcm2835_wdt.c:__bcm2835_restart in Linux.
Ah, I was looking at this just today, as it had been annoying me
greatly. This works for me, so:
Tested-by: Corey Minyard <cminy...@mvista.com>
However, I was wondering if it might be better to handle this by failing
the operation in xen and passing it back to dom0 to do. On the Pi you
send a firmware message to reboot, and that seems like too much to do in
Xen, but it would seem possible to send this back to dom0.
I don't think this is possible in the current setup. Xen will usually
restart the platform if Dom0 requested a clean reboot or crashed. So the
domain wouldn't be in state to service such call.
Ok, I hadn't looked at Xen yet, I didn't know how much shutdown of dom0
happens on a reset.
Just a
thought, as it might be a more general fix for other devices in the same
situation.
What are the devices you have in mind?
Nothing in particular, but other systems might have the same issue. I
guess you have ACPI implemented on x86 already. It just seemed that
Linux already has to be able to do this, and passing the buck back there
might be a more general solution.
I don't really see how you can make a generic solution here. Each
devices may have a different way to act.
For anything related to power control, the right solution is to
implement PSCI/SCMI in your firmware so you don't need to rely on Dom0
(which may not exist) for such thing.
Cheers,
--
Julien Grall