We have lost our frame buffer on AM62x

Hi guys,

We've been focusing a lot on our legacy am57x board in our layer.
So it is highly likely that I somehow broke this in the am62x portion.
I guess I am looking for help on where to start.

Basically, I've got no /dev/fb0 device anymore. So psplash doesn't launch...

root@mitysom-am62x-ep00119:~# psplash
Error opening /dev/fb0

I do see this in dmesg on start up and whenever I plug in the usb/hdmi display.

[ 9024.250083] OF: graph: no port node found in /bus@f0000/dss@30200000/oldi-txes/oldi@0/ports
[ 9024.258547] OF: graph: no port node found in /bus@f0000/dss@30200000/oldi-txes/oldi@1/ports

Checking the config for frame buffer related thingies...

root@mitysom-am62x-ep00119:~# cat /proc/config.gz | gunzip | grep CONFIG_FB | grep -v ^#
CONFIG_FB=y
CONFIG_FB_SIMPLE=y
CONFIG_FB_CORE=y
CONFIG_FB_NOTIFY=y
CONFIG_FB_DEVICE=y
CONFIG_FB_CFB_FILLRECT=y
CONFIG_FB_CFB_COPYAREA=y
CONFIG_FB_CFB_IMAGEBLIT=y
CONFIG_FB_SYS_FILLRECT=y
CONFIG_FB_SYS_COPYAREA=y
CONFIG_FB_SYS_IMAGEBLIT=y
CONFIG_FB_SYS_FOPS=y
CONFIG_FB_DEFERRED_IO=y
CONFIG_FB_DMAMEM_HELPERS=y
CONFIG_FB_IOMEM_FOPS=y
CONFIG_FB_IOMEM_HELPERS=y
CONFIG_FB_SYSMEM_HELPERS=y
CONFIG_FB_SYSMEM_HELPERS_DEFERRED=y
CONFIG_FB_MODE_HELPERS=y

Our image is basically... (broken up over a couple of different includes, I've merged them here)

require recipes-core/images/arago-image.inc

ARAGO_BASE_IMAGE_EXTRA_INSTALL ?= "\
    psplash \
    audit \
    git-revisions \
    swupdate \
    swupdate-www \
    swupdate-cert \
    u-boot-fw-utils \
    pru-icss \
    packagegroup-arago-tisdk-crypto \
    gdbserver \
    ptpd \
" 

IMAGE_INSTALL += "\
    packagegroup-arago-base \
    packagegroup-arago-console \
    ${ARAGO_BASE_IMAGE_EXTRA_INSTALL} \
"

None of this stuff messes with graphics or frame buffers. I'm stumped.
Any help would be appreciated!

Thanks,
Nathan

Replies (6)

RE: We have lost our frame buffer on AM62x - Added by Jonathan Cormier 1 day ago

Can you check to see if the GPU driver is loaded? If you've been building custom kernels outside of yocto, its pretty easy to lose the gpu driver and that can break the /dev/fb0

root@mitysom-am62x:~# find  /lib/modules/ -name pvr*
/lib/modules/6.6.58-g-gd584bc2c0050/updates/pvrsrvkm.ko
root@mitysom-am62x:~# lsmod | grep pvr
pvrsrvkm ...

https://support.criticallink.com/redmine/projects/mitysom_am62x/wiki/Linux_Kernel_PVR

RE: We have lost our frame buffer on AM62x - Added by Nathan Wright 1 day ago

Gasp! Eureka, how did I lose those?

root@mitysom-am62x-ep00119:~# find  /lib/modules/ -name pvr*
root@mitysom-am62x-ep00119:~# lsmod | grep pvr
root@mitysom-am62x-ep00119:~#

Thanks that's probably the nudge I needed.

RE: We have lost our frame buffer on AM62x - Added by Nathan Wright about 24 hours ago

Hi Jon,

I have restored pvrsrvkm to the target by adding libgles2 recipe to the image.

root@mitysom-am62x-ep00119:~# find /lib/modules -name pvr*
/lib/modules/6.6.58-g-gd584bc2c0050-dirty/updates/pvrsrvkm.ko
root@mitysom-am62x-ep00119:~# lsmod | grep pvr
pvrsrvkm             1466368  0
drm                   667648  7 drm_kms_helper,drm_dma_helper,display_connector,pvrsrvkm,tidss,ti_tfp410

I still have no frame buffer though.

root@mitysom-am62x-ep00119:~# psplash
Error opening /dev/fb0
root@mitysom-am62x-ep00119:~# ls -la /dev/fb*
ls: /dev/fb*: No such file or directory
root@mitysom-am62x-ep00119:~# /usr/bin/fbtest
/usr/src/debug/kms++/2.1/utils/fbtest.cpp:24: int main(int, char**):
open /dev/fb0 failed

Aborted (core dumped)

Any other hints?

For reference, here is the merged recipe stack of our image with annotations...

require recipes-core/images/arago-image.inc
ARAGO_BASE_IMAGE_EXTRA_INSTALL ?= "\
    psplash \
    audit \          <--- a little script that checks the target build
    git-revisions \  <--- creates /etc/git-revisions with layer stack revisions
    swupdate \       <--- next 4 are all about os management
    swupdate-www \
    swupdate-cert \
    u-boot-fw-utils \
    pru-icss \         <--- so we can talk to the co processors
    libegl \           <--- next 2 gpu stuff
    libgles2 \
    glmark2 \          <--- gpu benchmarker
    packagegroup-arago-tisdk-crypto \
    gdbserver \
    ptpd \
" 
IMAGE_INSTALL += "\
    packagegroup-arago-base \
    packagegroup-arago-console \
    ${ARAGO_BASE_IMAGE_EXTRA_INSTALL} \
"

Thanks,
Nathan

RE: We have lost our frame buffer on AM62x - Added by Jonathan Cormier about 23 hours ago

Thanks Nathan, thats progress. Can you send me your dts/dtb and defconfig?

RE: We have lost our frame buffer on AM62x - Added by Nathan Wright about 20 hours ago

In attempting to gather that info, I saw that there were some upstream changes to the devkit dts file that our copy did not have.

After syncing our dts with the devkit dts, the frame buffer is back!

Thanks for your help.

RE: We have lost our frame buffer on AM62x - Added by Jonathan Cormier about 20 hours ago

Great, good to hear

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