Hi Olof,


On 10 May 2013 11:51, Vikas Sajjan <vikas.sajjan@linaro.org> wrote:
Hi Olof,


On 10 May 2013 11:08, Olof Johansson <olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org> wrote:
On Thu, May 9, 2013 at 7:55 PM, Vikas Sajjan <vikas.sajjan-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> Hi Tomasz,
>
>
> On 10 May 2013 05:35, Tomasz Figa <tomasz.figa-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>>
>> Hi Vikas,
>>
>> On Wednesday 08 of May 2013 11:31:34 Vikas Sajjan wrote:
>> > Adds display timing node for a DP panel to Arndale Board DTS file
>> >
>> > Signed-off-by: Vikas Sajjan <vikas.sajjan-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>> > ---
>> >  arch/arm/boot/dts/exynos5250-arndale.dts |   16 ++++++++++++++++
>> >  1 file changed, 16 insertions(+)
>> >
>> > diff --git a/arch/arm/boot/dts/exynos5250-arndale.dts
>> > b/arch/arm/boot/dts/exynos5250-arndale.dts index f68b820..c831a5c
>> > 100644
>> > --- a/arch/arm/boot/dts/exynos5250-arndale.dts
>> > +++ b/arch/arm/boot/dts/exynos5250-arndale.dts
>> > @@ -459,4 +459,20 @@
>> >               samsung,lane-count = <4>;
>> >       };
>> >
>> > +     display-timings {
>> > +             native-mode = <&timing0>;
>> > +             timing0: timing@0 {
>> > +                     /* 2560x1600 DP panel */
>> > +                     clock-frequency = <50000>;
>> > +                     hactive = <2560>;
>> > +                     vactive = <1600>;
>> > +                     hfront-porch = <48>;
>> > +                     hback-porch = <80>;
>> > +                     hsync-len = <32>;
>> > +                     vback-porch = <16>;
>> > +                     vfront-porch = <8>;
>> > +                     vsync-len = <6>;
>> > +             };
>> > +     };
>>
>> What display are those timings used for? Shouldn't they be placed inside
>> node of that display?
>>
>
> This timing information will be used parsed by the FIMD probe with the help
> of "Video Helper function"  as done in this link
>
> https://git.kernel.org/cgit/linux/kernel/git/daeinki/drm-exynos.git/commit/?h=exynos-drm-next&id=7f4596f4aebcc9fcf2d50d3fe398508d710c4dd0

That function passes in a device node pointer to the FIMD device node,
and only looks for a display-timings node under there. Tomasz is
right, as far as I can tell.

Placing display timings at the root of the device tree seems completely wrong.

        I referred this " Documentation/devicetree/bindings/video/display-timing.txt" for example

            here it dosen't mention about whether display timings node can be placed at the root of the device tree or NOT.
 Not sure how we should be placing the node then.
 
 
That needs to be fixed up as well, thanks for pointing it out.


-Olof



--
Thanks and Regards
 Vikas Sajjan



--
Thanks and Regards
 Vikas Sajjan