From mboxrd@z Thu Jan  1 00:00:00 1970
From: Greg KH <gregkh@linuxfoundation.org>
Subject: Re: [REPOST PATCH 1/8] fence: dma-buf cross-device synchronization
 (v17)
Date: Thu, 19 Jun 2014 13:01:59 -0700
Message-ID: <20140619200159.GA27883@kroah.com>
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To: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-arch@vger.kernel.org, Thomas Hellstrom <thellstrom@vmware.com>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>, "linaro-mm-sig@lists.linaro.org" <linaro-mm-sig@lists.linaro.org>, Colin Cross <ccross@google.com>, "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>
List-Id: dri-devel@lists.freedesktop.org

On Thu, Jun 19, 2014 at 09:15:36PM +0200, Daniel Vetter wrote:
> On Thu, Jun 19, 2014 at 7:00 PM, Greg KH <gregkh@linuxfoundation.org> wrote:
> >> >> +     BUG_ON(f1->context != f2->context);
> >> >
> >> > Nice, you just crashed the kernel, making it impossible to debug or
> >> > recover :(
> >>
> >> agreed, that should probably be 'if (WARN_ON(...)) return NULL;'
> >>
> >> (but at least I wouldn't expect to hit that under console_lock so you
> >> should at least see the last N lines of the backtrace on the screen
> >> ;-))
> >
> > Lots of devices don't have console screens :)
> 
> Aside: This is a pet peeve of mine and recently I've switched to
> rejecting all patch that have a BUG_ON, period.

Please do, I have been for a few years now as well for the same reasons
you cite.

greg k-h