Dear All,
We are using OMAP3530 processor for one of our project & we facing some issues regarding LCD interfacing.
Please find all the details & issues bellow
Processor : OMAP3530
Development board : Beagleboard Rev C4
OS : Linux
Kernel Ver : 2.6.32
Rootfs distribution : Angstrom with X11
LCD panel : 5" 800x480 (datasheet attached)
LCD interface : 24 RGB
LCD interface board : Customized
LCD pixel clock : 30 Mhz (typical)
I have registered the LCD panel to dss device with following timings signals as given in LCD datasheet
.x_res = 800,
.y_res = 480,
.pixel_clock = 30000,
.hsw = 48,
.hfp = 40,
.hbp = 80,
.vsw = 3,
.vfp = 13,
.vbp = 32,
Now the issue is when I boot my system the LCD screen start flickering, here the flickering is not due to low
refresh rate but showing swapped double images and very distorted display. Even this flickering is very less
in the initial screen(angstrom boot screen) but more in the later X11 desktop screen.
Please find the video of display at pixel clock 30 Mhz in below link:
http://www.youtube.com/watch?v=GDBWq-aO0eY
Then we started decreasing pixel clock and the flickering also decreased. At 16.4 Mhz of pixel clock this type of
flickering stopped but scanning flickering started due to low pixel clock resulting low refresh rate. In this case image
is stable.
Please find the video of display at pixel clock 16.4 Mhz in below link:
http://www.youtube.com/watch?v=W82WRW1-uQ8
Q1) Is X11 not able to fill the framebuffer properly to sync with fast pixel clock ???
Please let us know the proper way to handle this. ?
We wanted to run a GUI based QT application also having video to be executed simultaneously,
the display size of video & GUI app is 800x480.
Q2) Is this possible to run this smoothly with OMAP 3530 ???
Q3) What is use of following configuration of LCD panel
OMAP_DSS_LCD_IVS = 1<<0,
OMAP_DSS_LCD_IHS = 1<<1,
OMAP_DSS_LCD_IPC = 1<<2,
OMAP_DSS_LCD_IEO = 1<<3,
OMAP_DSS_LCD_RF = 1<<4,
OMAP_DSS_LCD_ONOFF = 1<<5,
OMAP_DSS_LCD_TFT = 1<<20,
We have configured this as
dssdev->panel.config = OMAP_DSS_LCD_TFT;
Q4) Is this proper ?
Please find the video of display at pixel clock 30 Mhz in below link:
http://www.youtube.com/watch?v=GDBWq-aO0eY
Please find the video of display at pixel clock 16.4 Mhz in below link:
http://www.youtube.com/watch?v=W82WRW1-uQ8
WAITING FOR SOMEONE'S REPLY
Regards...
Parth Joshi
Lumium