DM3730 + DSI LCD. Can't update frame buffer.

Garrikus Vulgaris

Other Parts Discussed in Thread: DM3730

Hello, everyone.

I'm trying to bring up Truly LCD panel in DSI comand mode on DM3730 Linux 2.6.37 platform. I'm using panel-taal.c driver as a reference.

So far it looks like I have DSI engine running fine. The panel is successfully probed for, frame buffer is created and updated on startup. I know that, because I've cleared vram ( in _omap_vram_clear() ) not with zeros but with 0x008800. So once the kernel is up I have nice green display. But when I try to update frame buffer with dd if=/dev/zero of=/dev/fb0 -- it has no effect on LCD.

Any pointers on why this might be happening?

over 12 years ago

0 Cvetolin Shulev-XID over 12 years ago

TI__Guru 65405 points

Hi Garrikus,

Could you specify what software you are using DVSDK or some kind of android?

Tsvetolin Shulev

0 Garrikus Vulgaris over 12 years ago in reply to Cvetolin Shulev-XID

Prodigy 230 points

Tsvetolin,

This is not Android.

My kernel is based on arago's OMAPPSP_04.02.00.07 branch here, which (as far as I understand) is what DVSDK's kernel is built from.

0 Garrikus Vulgaris over 12 years ago in reply to Garrikus Vulgaris

Prodigy 230 points

Well, the answer was dead simple. I have a manual udpate LCD, so I can't expect anything to appear on the screen simply by writing that anything to /dev/fb0. The kernel must be explicitly told by user space with ioctl(OMAPFB_UPDATE_WINDOW) to update LCD with framebuffer's contents. That's it.

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DM3730 + DSI LCD. Can't update frame buffer.