topic Re: mx6 dual display quality in i.MX Processors

mx6 dual display quality

Dennis_Han — Tue, 05 Mar 2013 23:54:32 GMT

hi.

I'm using custom board based on sabrelite.

basically, dual display is working fine.

but, fb1 for second display has bad quality issue.

please refer to attached pics.

this is my working bootargs.

setenv bootargs console=ttymxc1,115200 video=mxcfb1:dev=hdmi,1280x720M@60, if=RGB24 video=mxcfb0:dev=hdmi2,1280x720M@60,if=RGB24 fbmem=28M,28M vmalloc=192M, root=/dev/mmcblk0p1 rw rootwait consoleblank=0

i add sil9022 driver as the board designed and changed its name to hdmi2.

all works fine except bad quality.

HDMI ------------------------> fb1

RGB ------->sil9022 -----> fb0

both displays set to ipu 0 disp_id 0.

i think this causing my issue though, i don't know very much about IPU stuff.

i switched fb0 and fb1 to check whether it makes different. though, just same as before.

pleas help me out.

Re: mx6 dual display quality

VladanJovanovic — Wed, 06 Mar 2013 08:19:59 GMT

Looks like framebuffer has only 16-bit or less bits per pixel. Is it due to SIL9022 setup or a software config issue?

Re: mx6 dual display quality

Dennis_Han — Wed, 06 Mar 2013 08:31:50 GMT

HI !!!!

Thanks for the reply.

i swapped the fb order for both to test if the issue is related sii902x driver.

but, when sii902x (hdmi2) to fb0. it shows good quality.

so with fb0 both devices has no problem. but, with fb2 the problem arised. (with hdmi, or hdmi2 just same)

i tried bpp=32 option, 1280x720-32 mode string, IPU_PIX_FMT_RGB24 pixel format and V4L2_PIX_FMT_RGB24 for display. and so on.

all of them were not helpful.

is there anyhting i missed ?

Re: mx6 dual display quality

Dennis_Han — Thu, 07 Mar 2013 10:43:10 GMT

root@imx6qsabrelite:~# fbset -i -fb /dev/fb0

mode "1280x720-60"

# D: 74.250 MHz, H: 45.000 kHz, V: 60.000 Hz

geometry 1280 720 1280 720 32

timings 13468 178 56 24 1 136 5

hsync high

vsync high

rgba 8/16,8/8,8/0,8/24

endmode

Frame buffer device information:

Name : DISP3 BG

Address : 0x18000000

Size : 3686400

Type : PACKED PIXELS

Visual : TRUECOLOR

XPanStep : 1

YPanStep : 1

YWrapStep : 1

LineLength : 5120

Accelerator : No

root@imx6qsabrelite:~# fbset -i -fb /dev/fb2

mode "1280x720-60"

# D: 74.250 MHz, H: 45.000 kHz, V: 60.000 Hz

geometry 1280 720 1280 720 32

timings 13468 220 110 20 5 40 5

hsync high

vsync high

rgba 8/16,8/8,8/0,8/24

endmode

Frame buffer device information:

Name : DISP3 BG - DI1

Address : 0x18800000

Size : 3686400

Type : PACKED PIXELS

Visual : TRUECOLOR

XPanStep : 1

YPanStep : 1

YWrapStep : 1

LineLength : 5120

Accelerator : No

these are my fb settings for fb0 and fb2.

currently,

fb0 is mapped with hdmi2 (sil9022) -> it shows good quality.

fb1 is overlay for fb0

fb2 is mapped with hdmi (internal hdmi) -> it shows bad quality (seems 16 bit)

anybody any idea ?

Re: mx6 dual display quality

Dennis_Han — Fri, 08 Mar 2013 14:19:57 GMT

Now I got a solution.

I change hdmi ipu to 1,

now 0 for hdmi2 as in pinmuxed, 1 for hdmi (dynamic while kernel booting).

I still don't know why ipu dropped the bits.

maybe bandwidth issue ?