Linux/AM4379: Changing LCD resolution without rebooting

William tong

Part Number: AM4379

Tool/software: Linux

Hi all,

I want change the LCD resolution without rebooting the linux system.

I tried to do it with the "fbset -xres 800 -yres 600" but return info is like this"ioctl FBIOPUT_VSCREENINFO: Invalid argument"

The kernel I use is "Linux am437x-evm 3.14.43-g9709f05-dirty"

The chip is AM4379.

And I have researched the wed,and found a similar question.I tried the cmd,but couldn't make it.

On my board,the path /sys/devices/platform/omapdss only has four files ,namely "driver modalias power subsystem uevent".

Does the dss/fb driver support the function that change the resolution dynamically?

Could someone enlighten me?

Thanks in advance.

Regards,

William

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi,

The software team have been notified. They will respond here.

0 Yordan Kovachev over 8 years ago

TI__Guru**** 161600 points

Hi William,

1. Try fbset command:
processors.wiki.ti.com/.../Sitara_Linux_LCDC_fbdev_User_Space
2. Try adding the resolution in weston.ini (if your kernel uses weston, I don't recall what was used in 3.14). See the following thread:
e2e.ti.com/.../1895785

Best Regards,
Yordan

0 William tong over 8 years ago in reply to Yordan Kovachev

Prodigy 70 points

Hi Yordan,
Thanks for your reply.
1.I don't find any command about changing the resolution without rebooting the system on
processors.wiki.ti.com/.../Sitara_Linux_LCDC_fbdev_User_Space
And I have said that "I tried to do it with the "fbset -xres 800 -yres 600" but return info is like this"ioctl FBIOPUT_VSCREENINFO: Invalid argument" above.
I doubt that If the fb driver of the omapdrm do support the IOCTLs which change the resolution without rebooting?
Or could you tell me the right fbset command to change the LCD resolution ?
2.On the filesystem,I don't find anything about the weston.ini .

0 Yordan Kovachev over 8 years ago in reply to William tong

TI__Guru**** 161600 points

Hi,

2.On the filesystem,I don't find anything about the weston.ini .

There is another option, as I said, depending on your distribution version. You can use /etc/fb.modes:
stackoverflow.com/.../how-to-define-a-unsupported-screen-resolution-in-linuxs-framebuffer
www.kernel.org/.../framebuffer.txt

Best Regards,
Yordan

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Linux/AM4379: Changing LCD resolution without rebooting