From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eugeni Dodonov <eugeni@dodonov.net>
Subject: Re: [PATCH 05/29] drm/i915: prevent NULL pointer
 exception when using gmbus
Date: Fri, 13 Apr 2012 21:26:14 -0300
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To: Chris Wilson <chris@chris-wilson.co.uk>
Cc: intel-gfx@lists.freedesktop.org, Eugeni Dodonov <eugeni.dodonov@intel.com>
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On Fri, Apr 13, 2012 at 17:18, Chris Wilson <chris@chris-wilson.co.uk>wrote:

> On Fri, 13 Apr 2012 17:08:41 -0300, Eugeni Dodonov <
> eugeni.dodonov@intel.com> wrote:
> > Prevent a NULL pointer exception when we are trying to retrieve EDID data
> > from non-existent adapter.
>
> This just means that a HDMI with a garbage ddc_bus is never detected.
> Since we control ddc_bus entirely, it means that the initialisation is
> completely bogus. Please fix the root cause and not paper over
> programming bugs.
>

Sorry, I think I wasn't clear in my cover letter about this one.. I am not
hitting any issue with this current branch I sent; but the nature of the
code we have after the gmbus refactoring made me a bit paranoid about
accessing properties of something that could potential be NULL.

As far as I can see, we should not hit this with any combination of outputs
on any hardware that is already covered by the wikipedia :). So I am fine
with dropping this patch if you also think that it does not adds anything
relevant to us. Or perhaps I should refactor it into adding some WARN's
instead?

-- 
Eugeni Dodonov
<http://eugeni.dodonov.net/>

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<div class=3D"gmail_quote">On Fri, Apr 13, 2012 at 17:18, Chris Wilson <spa=
n dir=3D"ltr">&lt;<a href=3D"mailto:chris@chris-wilson.co.uk">chris@chris-w=
ilson.co.uk</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quote" styl=
e=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">

<div class=3D"im">On Fri, 13 Apr 2012 17:08:41 -0300, Eugeni Dodonov &lt;<a=
 href=3D"mailto:eugeni.dodonov@intel.com">eugeni.dodonov@intel.com</a>&gt; =
wrote:<br>
&gt; Prevent a NULL pointer exception when we are trying to retrieve EDID d=
ata<br>
&gt; from non-existent adapter.<br>
<br>
</div>This just means that a HDMI with a garbage ddc_bus is never detected.=
<br>
Since we control ddc_bus entirely, it means that the initialisation is<br>
completely bogus. Please fix the root cause and not paper over<br>
programming bugs.<br></blockquote><div><br></div><div><div>Sorry, I think I=
 wasn&#39;t clear in my cover letter about this one.. I am not hitting any =
issue with this current branch I sent; but the nature of the code we have a=
fter the gmbus refactoring made me a bit paranoid about accessing propertie=
s of something that could potential be NULL.</div>

<div><br></div><div>As far as I can see, we should not hit this with any co=
mbination of outputs on any hardware that is already covered by the wikiped=
ia :). So I am fine with dropping this patch if you also think that it does=
 not adds anything relevant to us. Or perhaps I should refactor it into add=
ing some WARN&#39;s instead?</div>

</div><div><br></div></div>-- <br>Eugeni Dodonov<a href=3D"http://eugeni.do=
donov.net/" target=3D"_blank"><br></a><br>

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