Identified commit that breaks vc4

[Hecatron]

Hi
I've recently been experimenting trying to get the vc4 drivers to work with 4.5
I've not got vc4 working fully yet (I still need to have a mess with some of the config settings which I think is the next problem)
But I've discovered that one of the commits in this tree prevents the system from booting if dtoverlay=vc4-kms-v3d is enabled in config.txt

The offending commit appears to be

commit 8924ecf62e9ee8ec991d6361152e17268cc7ed6f
Author: Eric Anholt <[email protected]>
Date:   Mon Oct 12 11:23:34 2015 -0700

    clk: bcm2835: Also build the driver for downstream kernels.

    Signed-off-by: Eric Anholt <[email protected]>

If I use the commit just before it then the system will boot (I still get a black screen but at least I can ssh onto the box
and look at dmesg to see what's going on with vc4)

# Working Version
git clone https://github.com/raspberrypi/linux.git test1
git checkout -b rpi-4.5.y origin/rpi-4.5.y
git checkout b47868e0b58e112a1bebee16e35144673e09643b

I'm using the default config make bcm2709_defconfig
and the dtb files I'm using are actually from the very latest version (since that one has the files for the rpi3 added in)

[popcornmix]

Perhaps @anholt could let us know if any additional commits are needed for vc4-kms-v3d use on 4.5 kernel.

[Hecatron]

• For info I did also try the config from https://people.freedesktop.org/~anholt/dotconfig-bcm2835-20160309.txt
• Also tried two different monitors
• Also I re-tried it after the repo was upped to 4.5-rc7 but with the same result
• Firmware is the latest pull from March the 11th master https://github.com/raspberrypi/firmware/commits/master

The build process I'm using includes

make -j4 zImage modules dtbs
make modules_install
scripts/mkknlimg arch/arm/boot/zImage /boot/kernel7-gentoo10-vc4.img
cp arch/arm/boot/dts/*.dtb* /boot/
cp arch/arm/boot/dts/overlays/*.dtb* /boot/overlays/

cmdline.txt

dwc_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1 root=/dev/sda3 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait cma=256M@512M

config.txt (uncommented bits)

kernel=kernel7-gentoo10-vc4.img
avoid_warnings=2
dtoverlay=vc4-kms-v3d

# default entries
dtparam=audio=on
hdmi_force_hotplug=1

The only thing left I can think of is to hookup something to the gpio to try and capture something from the gpio uart, since I can't see anything on screen, just that the capslock key stops responding on a usb attached keyboard

[Hecatron]

Hmm the new version drm-vc4-4.5 from anholt's repo doesn't boot on my rpi2 or rpi3 yet, but the caps lock key still keeps working. So I think it's a little closer

[JamesH65]

Closing due to lack of activity. Reopen if you feel this issue is still relevant.