Question about support dual screen with LVDS and HDMI.

hyobokahn · ‎08-14-2017

I'm working on iMX6Q and iMX6Solo.
I have question to support dual screen(mirror display) with LVDS and HDMI.

I work based on git://git.freescale.com/imx/fsl-arm-yocto-bsp.git -b imx-4.1.15-1.0.0_ga.
and I use build option with
$ MACHINE=imx6qsabresd source fsl-setup-release.sh -b imx6q-qt5 -e x11
$ bitbake fsl-image-qt5

I check each LVDS and HDMI work fine with video boot option like as:
LVDS test :           setenv video 'video=mxcfb0:dev=ldb,LDB-XGA,if=RGB24'
HDMI test :           setenv video 'video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24'
HDMI test :           setenv video 'video=mxcfb0:dev=hdmi,1024x768@30,if=RGB24'

but, I always fail when want to display LVDS and HDMI dual screen(simultinaous mirror screen).
I try most of wat to do support it, but I always I fail.
when I test with
setenv video 'video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24 video=mxcfb1:dev=ldb,LDB-XGA,if=RGB24'
the HDMI work only.
when I test with
setenv video 'video=mxcfb0:dev=ldb,LDB-XGA,if=RGB24 video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24'
th LVDS work only.

I think the mxcfb0 device only work.
I try to use ldb=dul0 or ldb=di0 option, but the source do not have parse routine for this operation.
I try dual mode on device tree, but have no effect too.
I test with fb, wayland and x11 backend, and all of result is same.

My question is "How can I enable dual screen on the iMX6Q and iMX6S?"
I guess, it must have patch for dual screen support. How can I get dual screen display patch?

I have one more question.
I hope to use iMX6Q and iMX6Solo use with one image.
but, I found there are machine option with imx6qsabresd and imx6solosabresd.
I guess iMX6Q and Solo is different in number of CPU, and peripheral is same, am I right?
can I use imx6qsabresd machine option for both of iMX6Q and iMX6Solo device?

if not, what is different between two options?

Thanks.

Rita_Wang · ‎08-15-2017

Hi,

About your another question,

About the images on i.MX6Q and i.MX6Solo you can not use the same images. The hardware and solftware design is different of these two chip. The hardware is not compatible between i.MX6Q and i.MX6Solo. So you can not do your above actions.

Have a nice day

Rita

hyobokahn · ‎08-15-2017

I see both of iMX6Q and iMX6Solo use same kernel configuration, imx_v7_defconfig.

So, I guess both of device have same hardware except the number of CPU, operation speed and some small difference in peripheral.

am I wrong?

May I know, detail difference between iMX6Q and iMX6Solo?

I cannot find any document to compare it.

Thanks.

Rita_Wang · ‎08-15-2017

Hi,

About the difference you can see the http://cache.nxp.com/docs/en/brochure/FLYRIMXPRDCMPR.pdf?fsrch=1&sr=1&pageNum=1 .

Have a nice day

Rita

hyobokahn · ‎08-16-2017

Hi Rita.

Thank you very much.

Rita_Wang · ‎08-15-2017

Hi,

About your first question please try procedures described in sect.4.7 Running Linux OS on the target

attached Linux Guide.
Have a great day,
Rita

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hyobokahn · ‎08-15-2017

Thanks for your reply.

I try all of instruction on the manual, but I fail.

always show first frame buffer device(mxcfb0) show screen.

I enable blank both of LVDS and HDMI.

I try most of recommend on the Community. but everything is not work, I fail.

I build Yocto by use following sources and backend.

this is step to build my image.

$ repo init -u git://git.freescale.com/imx/fsl-arm-yocto-bsp.git -b imx-4.1.15-1.0.0_ga

$ MACHINE=imx6qsabresd source fsl-setup-release.sh -b imx6q-qt5 -e fb

$ bitbake fsl-image-qt5

I fix device tree to support LVDS timing and it works fine.

I try most device tree option to support dual screen on the community.

But, I cannot display same screen on the both of LVDS and HDMI simultaniously.

Here is my device tree source

---------------------------------- imx6qdl-sabresd.dtsi ----------------------------------

&ldb {
status = "okay";
dual-mode;

        lvds-channel@0 {
                fsl,data-mapping = "spwg";
                fsl,data-width = <24>;
                status = "okay";
                primary;

                display-timings {
                        native-mode = <&timing0>;
                        timing0: hsd100pxn1 {
                                clock-frequency = <65000000>;
                                hactive = <1024>;
                                vactive = <768>;
                                hback-porch = <170>;
                                hfront-porch = <14>;
                                vback-porch = <29>;
                                vfront-porch = <3>;
                                hsync-len = <70>;
                                vsync-len = <6>;
                        };
                };
        };
};

---------------------------------- imx6q-sabresd.dts ----------------------------------

&ldb {
        lvds-channel@0 {
                crtc = "ipu2-di0";
        };

        lvds-channel@1 {
                crtc = "ipu2-di1";
        };
};

---------------------------------------------------------------------------------------------

Here is my boot option

U-Boot> setenv displayinfo 'video=mxcfb1:dev=ldb video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24'

I think the boot option is not everything to do, it look like there are something else.

I guess, I use wrong source or missing dual screen patch.

or, is there any clear step to enable LVDS and HDMI dual screen?

- new kernel patch (or newest kernel source)

: if I use wrong source, where can I get the source for support LVDS and HDMI dual screen?

- Uboot options

- device tree implementation

Thanks.

Rita_Wang · ‎08-16-2017

Hi,

I have confirmed and tested on my board. So sorry that the linux L4.1.15_2.0.0 BSP in our website do not support dual screen display. We do not have solutions and code about it. Linux BSP doesn't support dual display based on X11 by default, if you want to use dual display, you can use wayland-weston , please refer to the link :

i.mx6q Enable Dual Display of Ubuntu .

Some our customer have realized the dual display by modify the application code on QT, you maybe can go google to search related function.
Have a great day,
Rita

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hyobokahn · ‎08-16-2017

Hi Rita.

Thanks for your answer.

I'll check the way.

Rita_Wang · ‎08-15-2017

About the dual display I will do further confirming for you. And then give you reply.