IMX6SD Screen Resolution

[leonardopolito]

Hello everyone,

I recently bought the SabreBSD because I am fascinated by the embedded world!

I succesfully run the images provided, so Android and Gnome mobile images!

The really silly question now is:

How to change the screen resolution?

As read in the specification, I already tried to do it trough uboot, it works, it initialize the resolution as defined, but when the rootfs is mounted, the OS resolution will drop to 640x480, both with Android and Gnome!

Can I change the resolution somehow?

I'm using the HDMI output, on a DVI screen!

Thank you!!

[jorgepereira]

Hello,

I would like to know if imx6 sabreSD can display 1920x720 resolution through HDMI or there is any known issue.

Best regards..

[daiane_angolini]

I´ve been using video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24 in kernel command line with my HDMI monitor and it´s working OK

Regarding known issues, please see the Release Notes of the release you are using.

[daiane_angolini]

leonardopolito, Do you have another monitor?

Do you have another board?

My sabre SD can reach 1080p when I use HDMI on my monitor, so it´s hard to me reproduce your problem.

If you have other monitor, or other test scenario, please, let us know!

[PradapRaj]

FYI, We had encountered the same problem when we test with one monitor. Then we changed the monitor and problem gone.

While analyzing the issue, we found that Freescale has changed the implementation in the Latest Linux BSP release as mentioned above.

The monitor which was not working supports max of 14440x900 resolution and some more resolutions. But none of the resolution which monitor supports was matched with BSP supported resolution other than 640x480.

Then we used previous Linux Release with same monitor and same i.MX6 board, this problem didn't occur and displayed 14440x900 images on HDMI.

Regards,

Pradap

[leonardopolito]

Thank you for answers!

I've tried with 3 monitors:

2 Dell 2009W, 1680x1050p-59 || 1680x1050p-60

1 1680x1050p-60 (don't remember the model)

When no cable is connected, I can see on the board 1680x1050p-59 supported, so I don't really know why it happens!

Timings maybe?

The funny things is that with the 2/weeks old Android image, the uboot worked fine, so i had the penguin displayed at correct resolution, but Andorid drop it to 640x480 again!

The new Android image (2 days ago) give me kernel panic!

My Sabre is very old, it has some hand soldered green cable, but I'm not sure it's an hardware problem!

[daiane_angolini]

my sabreSD is very old as well. And I did remove u12 in order to get newest kernel to boot.

In other hand, I have u12 removed some weeks ago, and I did not see this android variation.

Are the kenrel crash rellated with USB?

[leonardopolito]

I did not investigate on that problem, I will do it tonight!

Do I need to remove U12? I have it on my board!

[daiane_angolini]

I removed mine.

Please, take a look if your error is related with USB. And please double check the release notes! The u12 information is there!

(this way you can see if, in your case, you need to remove it or not :smileywink:)

[daiane_angolini]

Can you, please, do me a favor?

find the "modes" file:

cd /

find -name modes

Next step

cat /path/to/modes

And please share with me results. (Sorry, I never remember where the file is located, shame on me)

I think edid is taking back a low resolution for your monitor, but let me be sure...

One more thing, you will need to decide regarding FB number. try fb0 at first.

[leonardopolito]

Thank you again for support!

result is:

V:640x480p-60

U:640x480p-60

[leonardopolito]

Am I wrong or there should be more resolution available?

[daiane_angolini]

Well, you´re right...

Usually we see much more resolutions.

But, if your cable or your monitor does not support more... then... you´re wrong :smileysilly:

[leonardopolito]

Ok, when no cable is connected, I can see a full list of available resolution, as soon as i connect the cable, just 640x480 appears!

It acts the same on 3 different DVI screen and with 2 different HDMI/DVI adapter!

How can I solve this problem?

[PradapRaj]

Freescale's Latest Linux BSP supports only the below mentioned resolutions for HDMI display.

1280x720p-59

1280x1024p-60

1024x768p-60

2880x480p-60

1920x1080p-24

1920x1080p-50

1280x720p-50

720x576p-50

720x576p-50

1920x1080p-60

1440x240p-60

1280x720p-60

720x480p-60

720x480p-60

640x480p-60

Also latest BSP's HDMI implementation is such a way that, It will check which of the BSP supported resolution is supporting by Monitor and then configure the matched resolution.I think the Monitor which you are using doesn't support any of the BSP supported resolution other than 640x480. So it configures 640x480p-60.

Regards,

Pradap

[leonardopolito]

Thank you!

This is the kernel boot command:

>setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/mmcblk1p1 rootwait rw video=mxcfb0:dev=hdmi, 1920x1080M@60,if=RGB24'

>boot

[daiane_angolini]

Can you share your kernel command line?