From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Tobias Schandinat Subject: Re: [PATCH] fb: do not ignore fb_set_par errors Date: Fri, 21 Aug 2009 19:42:09 +0200 Message-ID: <4A8EDC71.10403@gmx.de> References: <1250769597-14861-1-git-send-email-FlorianSchandinat@gmx.de> <1250769597-14861-2-git-send-email-FlorianSchandinat@gmx.de> <20090820153100.eec12070.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090820153100.eec12070.akpm@linux-foundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Andrew Morton Cc: linux-fbdev-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Andrew Morton schrieb: > On Thu, 20 Aug 2009 11:59:56 +0000 > Florian Tobias Schandinat wrote: > >> at the moment about half of the framebuffer drivers can return an error >> code in fb_set_par. Until now it would be silently ignored by fbmem.c >> and fbcon.c. The following patch fixes fbmem.c to pass it on but I have >> no idea what the right behaviour in fbcon.c would look like. >> Any comments? > > Nobody really maintains this code any more and I don't know to whom > your question should be addressed. All I can suggest is that you > decide what is the best path to take, and propose that we take it! Okay. I think it's difficult to ensure that we always end up with a working console. I assume that this is a very very rare case and as a start it should be enough to detect those cases and print an error message. > Yes, it seems reasonable to me - if we ignore this the machine will > probably crash later anyway. > > A well-behaved driver should leave the hardware in an unchanged state > if it's going to return an error (IMO). > > Do you know of any bug reports which are due to this lack of checking? No, I just hit the problem by thinking about how dynamic errors can be handled and looking at some drivers and fbmem.c. > If you're concerned about the effects of this change, perhaps you > should add a nice big printk when we decide to error out, so that it > makes it easier for bug reporters (and responders!) to work out what > happened? That's a very good idea. Will add this too and resend the patch. Thanks, Florian Tobias Schandinat