From:   Jani Nikula <jani.nikula@intel.com>
To:     "Lisovskiy, Stanislav" <stanislav.lisovskiy@intel.com>
Cc:     intel-gfx@lists.freedesktop.org, stable@vger.kernel.org
Subject: Re: [Intel-gfx] [RESEND 1/3] drm/i915/dsi: filter invalid backlight
 and CABC ports
In-Reply-To: <87mtc3p91d.fsf@intel.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
References: <cover.1660664162.git.jani.nikula@intel.com>
 <b0f4f087866257d280eb97d6bcfcefd109cc5fa2.1660664162.git.jani.nikula@intel.com>
 <YvyjILz4bXhvPjdZ@intel.com> <87mtc3p91d.fsf@intel.com>
Date:   Fri, 19 Aug 2022 12:52:26 +0300
Message-ID: <87mtc0o90l.fsf@intel.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Wed, 17 Aug 2022, Jani Nikula <jani.nikula@intel.com> wrote:
> On Wed, 17 Aug 2022, "Lisovskiy, Stanislav" <stanislav.lisovskiy@intel.com> wrote:
>> On Tue, Aug 16, 2022 at 06:37:20PM +0300, Jani Nikula wrote:
>>> Avoid using ports that aren't initialized in case the VBT backlight or
>>> CABC ports have invalid values. This fixes a NULL pointer dereference of
>>> intel_dsi->dsi_hosts[port] in such cases.
>>> 
>>> Cc: stable@vger.kernel.org
>>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>>
>> Would be interesting to figure out which one of those actually fixed the
>> https://gitlab.freedesktop.org/drm/intel/-/issues/6476 issue, this one
>> or next one.
>
> I asked to test with patch 1 alone first, and it lets them boot without
> the oops. And it produces the warn added here. But this just filters
> port C out of bl_ports, and doesn't fix the root cause. Patch 2 should
> fix the root cause, get rid of the warn and give them functioning
> backlight. I hope. There was no test results with patches 2&3. :)
>
>> Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
>
> Thanks for the review!

Also, pushed the series to drm-intel-next yesterday.

BR,
Jani.


-- 
Jani Nikula, Intel Open Source Graphics Center