Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) client-ip=2620:137:e000::3:2;
Date:   Thu, 07 Dec 2023 07:43:04 +0000
Message-ID: <87edfy8nlj.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Mukesh Ojha <quic_mojha@quicinc.com>
Cc:     <tglx@linutronix.de>, <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] irqchip/gic-v3-its: BUG_ON if stall bit is set
In-Reply-To: <1701929559-18252-1-git-send-email-quic_mojha@quicinc.com>
References: <1701929559-18252-1-git-send-email-quic_mojha@quicinc.com>
User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue)
 FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/28.2
 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO)
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset=US-ASCII
Precedence: bulk

On Thu, 07 Dec 2023 06:12:39 +0000,
Mukesh Ojha <quic_mojha@quicinc.com> wrote:
> 
> There could be various reason that stall bit could
> be set due to software errors while processing
> commands in command queue is being processed and

Such as?

> waiting for 1s is not going to help in debugging
> as command processing anyways going to be timed
> out and system will continue to run and may crash
> after some time due to this.
> 
> So, to debug such issues what command caused the
> stall bit to set, BUG_ON right away.

How on Earth will killing the system allow *anything* to be further
debugged?

If you need debug information, add the correct debug statements using
pr_debug(). Even better, try to gracefully recover from it if the ITS
command queue supports restarting.

Crashing the system is not an option.

	M.

-- 
Without deviation from the norm, progress is not possible.