From mboxrd@z Thu Jan  1 00:00:00 1970
From: vinod.koul@intel.com (Vinod Koul)
Date: Thu, 2 Nov 2017 22:03:40 +0530
Subject: [PATCH] dmaengine: dmatest: bug out when dma test times out
In-Reply-To: <36367ec9-61b1-9701-2dec-667b175ed90d@codeaurora.org>
References: <1509565797-5219-1-git-send-email-awallis@codeaurora.org>
 <20171102081758.GD3187@localhost>
 <21c3bb47-8ce6-fb53-9087-5f6bd3250bae@codeaurora.org>
 <36367ec9-61b1-9701-2dec-667b175ed90d@codeaurora.org>
Message-ID: <20171102163340.GI3187@localhost>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Thu, Nov 02, 2017 at 07:50:02AM -0500, Timur Tabi wrote:
> On 11/02/2017 07:11 AM, Adam Wallis wrote:
> >>This will essentially kill the system. People have been trying to remove
> >>usage of BUG(), we should not do that. Complaining violently makes sense..
> >>
> >Understood. In my testing, the system is effectively shot if you run the dmatest
> >in a tight enough loop, however, at least using a WARN would alert the user that
> >the kernel might be in an unstable state. I will submit another patch with a
> >WARN, even though, I hope a proper fix can be introduced at some point. I am not
> >familiar enough with this code to propose such a fix at the moment though.
> 
> I think Adam's original patch is correct, because as he said, the code as it
> is today corrupts the kernel.  The BUG() is a stop-cap measure to prevent
> the user from thinking that the kernel is stable when it isn't.

It also helps people to get more information to debug the systems

> So I think that either dmatest gets fixed properly today (which Adam said he
> cannot do), or you should apply his patch until the code can get fixed.

Ofcourse fixing is better.

-- 
~Vinod