Re: [EXT] Re: [PATCH v3 2/2] drm/panel: Add support for Raydium RM67191 panel driver

From: Robert Chiras
Date: Tue Jun 25 2019 - 02:35:28 EST

On Lu, 2019-06-24 at 13:12 -0300, Fabio Estevam wrote:
> Caution: EXT Email
> Hi Robert,
> On Mon, Jun 24, 2019 at 4:44 AM Robert Chiras <robert.chiras@xxxxxxx>
> wrote:
> >
> > >
> > > You did not handle the "power" regulator.
> > There is no need for a power regulator.
> I am sure the panel requires power to be applied so that it can work
> :-)
Yes, of course there are power lines to the panel. I will add them to
the next revision.
> >
> > >
> > > Can't you simply remove them?
> > The reset gpio pin is shared between the DSI display controller and
> Looking at the imx8mq-evk schematics it is not clear for me what pin
> in shared between the OLED display and touch screen.
> Could you please clarify which pin you are referring to?
It's about the DSI_EN pin on the DSI LCD IF physical port J1501. This
goes into RST_B_1V8 on the panel port which is used for both display
and touch resets.
> >
> > touch controller, both found on the same panel. Since, the touch
> > driver
> > also acceses this gpio pin, in some cases the display can be put to
> > sleep, but the touch is still active. This is why, during suspend I
> > release the gpio resource, and I have to take it back in resume.
> > Without this release/acquire mechanism during suspend/resume,
> > stress-
> > tests showed some failures: the resume freezes completly.
> Looking at the imx8mq-evk dts from the vendor tree I see that the
> touchscreen is not supported in mainline yet.
> Maybe there is a better way to solve this, so what if you don't
> introduce the suspend/resume hooks for now and then we revisit this
> after the touchscreen driver is added?
You are right. We can do this too. I will remove it for now.