Re: [PATCH v3 21/32] drm/exynos: Move dp driver from video/ to drm/

[Tomasz Figa <tomasz.figa@gmail.com>]

On Friday 01 of November 2013 08:55:12 Jingoo Han wrote:
> On Friday, November 01, 2013 8:27 AM, Tomasz Figa wrote:
> > On Friday 01 of November 2013 08:23:59 Jingoo Han wrote:
> > > On Friday, November 01, 2013 8:12 AM, Tomasz Figa wrote:
> > > > On Friday 01 of November 2013 08:06:00 Jingoo Han wrote:
> > > > > On Thursday, October 31, 2013 7:47 PM, Inki Dae wrote:
> > > > > > CCing Jingoo,
> > > > > > 
> > > > > > Is that ok to remove eDP driver from video/exynos? Isn't this
> > > > > > driver
> > > > > > really used by Linux framebuffer driver, s3c-fb.c?
> > > > > 
> > > > > +cc Tomi Valkeinen, Jean-Christophe PLAGNIOL-VILLARD,
> > > > > 
> > > > >      linux-fbdev list, linux-samsung-soc list
> > > > > 
> > > > > Yes, it is used by s3c-fb.c.
> > > > > 
> > > > > > Of course, now s3c-fb driver is dead code because this driver
> > > > > > doesn't
> > > > > > support device tree yet but we would need more reviews and
> > > > > > discussions
> > > > > > about moving this driver into drm side. Let's watch new rules
> > > > > > for
> > > > > > device tree bindings of DRM world. So I'd not like to merge
> > > > > > this
> > > > > > driver yet.
> > > > > 
> > > > > 's3c-fb' driver is still used for other mass products projects.
> > > > > Just, device tree support patch is not yet submitted.
> > > > 
> > > > Current in-tree users of s3c-fb drivers are s3c2443, non-DT
> > > > s3c64xx
> > > > and
> > > > all s5p* SoCs. It is not used on Exynos SoCs anymore.
> > > 
> > > Hi Tomasz Figa,
> > 
> > Just Tomasz. ;)
> 
> Hi Tomasz, :-)
> 
> > > Some mass product projects using Exynos5250 and etc, use s3c-fb
> > > driver
> > > and dp driver. Also, these projects are still using Framebuffer, not
> > > DRM.
> > 
> > Well, those are based on vendor trees anyway, so do not really affect
> > mainline kernel.
> 
> OK, I see.
> 
> > > > As for Exynos DP driver, what SoCs does it support? If only Exynos
> > > > (as
> > > > the name suggests) then there is no point in keeping it at
> > > > video/exynos and making it a part of Exynos DRM driver seems
> > > > reasonable to me.
> > > 
> > > However, when considering only mainline kernel, I have no strong
> > > objection. As you know, many Linux kernel based OS projects using
> > > Exynos, are using DRM, not Framebuffer.
> > 
> > Generally, fbdev is strongly discouraged in any new systems and DRM is
> > the way to go, so I don't think we should ever want to bring s3c-fb
> > support back to Exynos platforms.
> 
> Yes, you're right.
> Personally, I think that all Exynos platforms should go into DRM, not
> FB.
> 
> One more thing, then how about moving Exynos MIPI to DRM side?
> Is there any plan on Exynos MIPI?

Well, it will eventually have to be moved somewhere else than it is, but I 
believe this will have to wait for Common Display Framework.

This is because the case of MIPI DSI is slightly different from 
DisplayPort, since it is not an enumerable/auto-configurable interface and 
requires dedicated panel drivers and static data provided by board 
designers (in DT for example). Handling of such things in a generic way 
will be done by CDF.

Best regards,
Tomasz