topic Re: No output from LVDS in i.MX Processors

No output from LVDS

xiaochao0131 — Wed, 03 Aug 2016 07:46:10 GMT

I use u-boot 2016.03 and ubuntu Image(kernel 3.14.52), I want to use LVDS as default video output, I set the u-boot variable setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/mmcblk1p1 rootwait rw video=mxcfb0:dev=ldb, LDB-XGA,1024x768M@60,if=RGB666'. The LVDS panel backlight flick several times then stoped. The video is always output from HDMI. Could you tell me how to set the LVDS as default output?

Below is my environment parameters:

Hit any key to stop autoboot: 0

=> printenv

active_partition=1

baudrate=115200

board=sabrelite

bootargs=cpu= board=

bootargs_mmc=setenv bootargs ${bootargs} root=/dev/mmcblk1p1 rootwait rw video=mxcfb0:dev=ldb,LDB-XGA,ldb=sin1,1024x768M@60,if=RGB666

bootcmd=script=/6x_bootscript;run runscript;setenv stdout serial,vga; echo ; echo 6x_bootscript not found ; echo ; echo serial console at 115200, 8N1 ; echo ; echo detai;

bootdelay=3

bootdevs=sata mmc usb

clearenv=if sf probe || sf probe ; then sf erase 0xc0000 0x2000 && echo restored environment to factory default ; fi

cmd_hdmi=fdt set fb_hdmi status okay;fdt set fb_hdmi mode_str 1280x720M@60;

cmd_lcd=fdt set fb_lcd status disabled

cmd_lvds=fdt set fb_lvds status okay;fdt set fb_lvds mode_str hannstart7;

console=ttymxc1

cpu=6Q

dfu_alt_info=u-boot raw 0x0 0xc0000

eth1addr=00:19:b8:00:00:02

ethact=FEC

ethprime=FEC

fb_lvds=hannstart7

fb_lvds2=hannstar

fdt_addr=13000000

fdt_high=0xffffffff

fileaddr=10008000

filesize=1155

initrd_high=0xffffffff

loadaddr=0x12000000

loadsplash=if sf probe ; then sf read ${splashimage} ${splashflash} ${splashsize} ; fi

mmc_disks=0 1

mmc_ums_disks=0 1

net_upgradeu=dhcp 10008000 net_upgradeu && source 10008000

otg_upgradeu=run usbnetwork; tftp 10008000 net_upgradeu && source 10008000

reset_cause=1

rundfu=dfu 0 sf 0:0:25000000:0

runscript=for dtype in ${bootdevs}; do if itest.s usb == ${dtype} ; then usb start ;fi; disks=${mmc_disks};if itest.s mmc != ${dtype} ; then disks=0;fi; for disk in ${di;

sfname=SST25VF016B

splashflash=c2000

stdin=serial,usbkbd

stdout=serial,vga

uboot_defconfig=nitrogen6q

umsdevs=sata mmc

upgradeu=script=/6x_upgrade; run runscript

usbnet_devaddr=00:19:b8:00:00:02

usbnet_hostaddr=00:19:b8:00:00:01

usbnetwork=setenv ethact usb_ether; setenv ipaddr 10.0.0.2; setenv netmask 255.255.255.0; setenv serverip 10.0.0.1;

usbrecover=run usbnetwork;setenv bootargs console=${console},115200; tftpboot 10800000 10.0.0.1:uImage-${board}-recovery && tftpboot 12800000 10.0.0.1:uramdisk-${board}-0

Environment size: 2673/8188 bytes

Re: No output from LVDS

igorpadykov — Wed, 03 Aug 2016 23:40:59 GMT

please look at below link describing BD ubuntu usage

https://boundarydevices.com/mx-linux-kernel-3-14-52/

Best regards

igor

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Re: No output from LVDS

xiaochao0131 — Thu, 04 Aug 2016 00:55:25 GMT

Hi igor,

I saw the link but it doesn't resolve my issue. I tried set the LVDS parameters as below, but no effect at all.

Hit any key to stop autoboot: 0

=> setenv fb_lvds hannstar7

=> saveenv

=> reset

Re: No output from LVDS

danwei_luo — Thu, 04 Aug 2016 03:06:44 GMT

Hi,

I think you can try following setting:

setenv bootargs_mmc setenv bootargs ${bootargs} root=/dev/mmcblk1p1 rootwait rw video=mxcfb0:dev=ldb,bpp=32

And also since you mentioned "The video is always output from HDMI", so I think you may remove HDMI connection first to test it. If you want LVDS and HDMI dual display, you can try this setting:

setenv bootargs_mmc setenv bootargs ${bootargs} root=/dev/mmcblk1p1 rootwait rw video=mxcfb0:dev=ldb video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24

Detail info you can refer to i.MX_Linux_User's_Guide.pdf, chapter 4.7.

Best regards,

Danwei Luo

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Note: If this post answers your question, please click the Correct Answer button. Thank you!

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Re: No output from LVDS

xiaochao0131 — Thu, 04 Aug 2016 03:19:12 GMT

Hi,

Thanks for your reply.

I removed the HDMI and found the LVDS shows "u-boot 2016.03 ....", I checked the serial port, it hangs on below message,

the board will reset serial times then hang on below message. But I remove LVDS and insert the HDMI, it will boot to ubuntu normally.

AHCI 0001.0300 32 slots 1 ports 3 Gbps 0x1 impl SATA mode

flags: ncq stag pm led clo only pmp pio slum part

No port device detected!

** Bad device size - sata 0 **

MMC: no card present

** Bad device mmc 0 **

switch to partitions #0, OK

mmc1 is current device

4437 bytes read in 30 ms (143.6 KiB/s)

## Executing script at 10008000

** File not found uEnv.txt **

42869 bytes read in 1209 ms (34.2 KiB/s)

only CEA modes allowed on HDMI port

----------- trying to load /initrd.img

2317536 bytes read in 280 ms (7.9 MiB/s)

5499904 bytes read in 501 ms (10.5 MiB/s)

Kernel image @ 0x10800000 [ 0x000000 - 0x53ec00 ]

## Flattened Device Tree blob at 13000000

Booting using the fdt blob at 0x13000000

reserving fdt memory region: addr=13000000 size=b000

Using Device Tree in place at 13000000, end 1300dfff

Re: No output from LVDS

xiaochao0131 — Thu, 04 Aug 2016 03:44:54 GMT

Everytime the board reset, the log from serial console is like this:

U-Boot 2016.03-20415-ged95621 (Jul 07 2016 - 17:28:42 -0700), Build: jenkins-uboot_v2016.03-64

CPU: Freescale i.MX6Q rev1.2 at 792 MHz

Reset cause: POR

Board: SABRE Lite

I2C: ready

DRAM: 1 GiB

MMC: FSL_SDHC: 0, FSL_SDHC: 1

SF: Detected SST25VF016B with page size 256 Bytes, erase size 4 KiB, total 2 MiB

Display: lvds:hannstar (1024x768)

In: serial

Out: serial

Err: serial

Net: Micrel ksz9021 at 6

FEC [PRIME]

Error: FEC address not set.

, usb_ether

Hit any key to stop autoboot: 0

AHCI 0001.0300 32 slots 1 ports 3 Gbps 0x1 impl SATA mode

flags: ncq stag pm led clo only pmp pio slum part

No port device detected!

** Bad device size - sata 0 **

MMC: no card present

** Bad device mmc 0 **

switch to partitions #0, OK

mmc1 is current device

4437 bytes read in 30 ms (143.6 KiB/s)

## Executing script at 10008000

** File not found uEnv.txt **

42869 bytes read in 1209 ms (34.2 KiB/s)

only CEA modes allowed on HDMI port

----------- trying to load /initrd.img

2317536 bytes read in 279 ms (7.9 MiB/s)

5499904 bytes read in 501 ms (10.5 MiB/s)

Kernel image @ 0x10800000 [ 0x000000 - 0x53ec00 ]

## Flattened Device Tree blob at 13000000

Booting using the fdt blob at 0x13000000

reserving fdt memory region: addr=13000000 size=b000

Using Device Tree in place at 13000000, end 1300dfff

Starting kernel ...

fec 2188000.ethernet (unregistered net_device): Invalid MAC address: 00:00:00:00:00:00

snvs_rtc 20cc034.snvs-rtc-lp: can't get snvs-rtc clock

fsl-hdmi-dai hdmi_audio.3: failed to probe. Load HDMI-video first.

imx-audio-hdmi sound-hdmi.19: initialize HDMI-audio failed. load HDMI-video first!

imx6q-pcie 1ffc000.pcie: phy link never came up

imx6q-pcie 1ffc000.pcie: Failed to bring link up!

imx6q-pcie 1ffc000.pcie: failed to initialize host

Re: No output from LVDS

xiaochao0131 — Thu, 04 Aug 2016 05:18:03 GMT

Below is my solution:

env default -f -a

setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/mmcblk1p1 rootwait rw video=mxcfb0:dev=ldb,LDB-XGA,1024x768M@60,if=RGB666'

setenv fb_lvds hannstar //Because my LVDS panel's solution is 1024x768

saveenv

reset

After doing above steps, the LVDS only shows "U-boot 2016.03......" , then I power off the board and power on it several seconds. The LVDS panle is on.