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

[Tim Harvey]

On Thu, Dec 9, 2021 at 12:36 AM Michael Nazzareno Trimarchi
<michael at amarulasolutions.com> wrote:
>
> 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,

Where can I find your patches?

What do you mean by etnaviv not being stable?

I did some limited testing with etnaviv on imx8mm with 5.15 + dsi
patches on an Ubuntu focal root filesystem by:
apt update
apt install gnome-session gnome-terminal
^^^ 2D hardware acceleration appears to be working (dragging opaque
windows around)
apt install mesa-utils glmark2
glxgears
^^^ ~160fps on IMX8MM
glmark2
^^^ score of 39 on IMX8MM

I haven't seen any updates from Jagan since Nov 24
(https://www.spinics.net/lists/dri-devel/msg324059.html) and am not
sure if he's been able to work through drm/exynos issues that have
been blocking his progress.

Best regards,

Tim