Re: [PATCH v10 5/5] Watchdog: ARM SBSA Generic Watchdog half timeout panic support

From: Timur Tabi
Date: Fri Feb 05 2016 - 08:08:36 EST


Thomas Petazzoni wrote:
if panic is enabled :
>|--------WOR-------WS0--------WOR-------WS1
>|------timeout------(panic)------timeout-----reset

I'm quite certainly missing something completely obvious here, but how
can you get the WS1 interrupt*after* raising a panic? Aren't all
interrupts disabled and the system fully halted once you get a panic(),
especially when raised from an interrupt handler? If that's the case,
how can the system continue to do things, such as receiving the WS1
interrupt and resetting ?

Typically, WS1 is not an interrupt. Instead, it's a hard system-level reset.

The hardware is capable of generating an interrupt for both WS0 and WS1. However, the ACPI table only contains one interrupt value, and it's not clear whether that's supposed to be the WS0 interrupt or the WS1 interrupts.

So this whole thing does assume a specfic watchdog configuration.

--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the
Code Aurora Forum, hosted by The Linux Foundation.