[RFC PATCH 00/17] drm: bridge: Samsung MIPI DSIM bridge

[Michael Nazzareno Trimarchi]

Hi Tim

On Tue, Oct 5, 2021 at 11:43 PM Tim Harvey <tharvey at gateworks.com> wrote:
>
> On Sun, Jul 25, 2021 at 10:14 AM Jagan Teki <jagan at amarulasolutions.com> wrote:
> >
> > Hi Sam,
> >
> > On Sun, Jul 25, 2021 at 10:35 PM Sam Ravnborg <sam at ravnborg.org> wrote:
> > >
> > > Hi Jagan,
> > >
> > > On Sun, Jul 04, 2021 at 02:32:13PM +0530, Jagan Teki wrote:
> > > > This series supports common bridge support for Samsung MIPI DSIM
> > > > which is used in Exynos and i.MX8MM SoC's.
> > > >
> > > > The final bridge supports both the Exynos and i.MX8MM DSI devices.
> > > >
> > > > Right now bridge offers two sets of implementations.
> > > >
> > > > A. With component_ops and exynos specific code exclusively for
> > > >    exynos dsi drivers and it's legacy bindings.
> > > >
> > > > B. Without componenet_ops for newly implemented bridges and its
> > > >    users like i.MX8MM.
> > > >
> > > > The future plan is to fix the implementation A) by dropping
> > > > component_ops and fixing exynos specific code in order to make
> > > > the bridge more mature to use and the same is mentioned in
> > > > drivers TODO.
> > > >
> > > > Patch 0001 - 0006: Bridge conversion
> > > > Patch 0007 - 0017: Samsung MIPI DSIM bridge fixes, additions
> > > >
> > > > Tested in Engicam i.Core MX8M Mini SoM.
> > > >
> > > > Anyone interest, please have a look on this repo
> > > > https://github.com/openedev/linux/tree/070421-imx8mm-dsim
> > > >
> > > > Would appreciate anyone from the exynos team to test it on
> > > > the exynos platform?
> > > >
> > > > Any inputs?
> > >
> > > I really like where you are headign with this!
> > > No testing - sorry. But I will try to provide a bit of feedback on the
> > > individual patches.
> > >
> > > I hope you find a way to move forward with this.
> >
> > Thanks for the response.
> >
> > We have found some issues with Bridge conversion on existing exynos
> > drivers. The component based DSI drivers(like exynos) are difficult to
> > attach if it involves kms hotplug. kms hotplug would require drm
> > pointer and that pointer would only available after the bind call
> > finishes. But the bridge attach in bind call will defer till it find
> > the attached bridge.
> >
> > Right now I'm trying to find the proper way to attach the bridges for
> > component based DSI drivers which involves kms hot-plug.
> >
> > If you have any ideas on this, please let me know.
> >
>
> Jagan,
>
> How is your progress on this series? Looking at your repo it looks
> like you've rebased on top of 5.13-rc3 in your 070121-imx8mm-dsim
> branch but you've got a lot of things there that are likely not
> related to this series?

I have a bit of work on those patches and tested on imx8mn. Basically:

- add the dsi timing calculation
- change few difference with samsung bridge
- fix crashes of my dsi panels
- compare with NXP driver the final results

I found that I have one problem that gives me some instability. In the
NXP original driver the panel needs to be
enabled in bridge_enable before out the standby. If I understand
correctly, our standby should be done after.
I would like to have some feedback and help and testing on other
boards/devices and some suggestions on how to handle
some of the differences. Another big problem is etnavi that is not stable

Michael

>
> Best regards,
>
> Tim
>
>


-- 
Michael Nazzareno Trimarchi
Co-Founder & Chief Executive Officer
M. +39 347 913 2170
michael at amarulasolutions.com
__________________________________

Amarula Solutions BV
Joop Geesinkweg 125, 1114 AB, Amsterdam, NL
T. +31 (0)85 111 9172
info at amarulasolutions.com
www.amarulasolutions.com