PL111 regression in v4.19-rc1

[Linus Walleij]

On Mon, Aug 27, 2018 at 2:43 PM Linus Walleij <linus.walleij at linaro.org> wrote:

> I'm trying to see if I can fix it, any hints welcome!

BTW this is pretty easy to reproduce in QEMU using a cross compilers:
I realized we were missing the VGA DAC when testing this...

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- versatile_defconfig
scripts/config --file .config --enable DRM_DUMB_VGA_DAC
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- dtbs
qemu-system-arm -M versatileab -no-reboot -kernel arch/arm/boot/zImage
-dtb arch/arm/boot/dts/versatile-ab.dtb -append "console=ttyAMA0"
-serial stdio -initrd rootfs-versatile.cpio

The initramfs/initrd is here:
https://dflund.se/~triad/krad/versatile/rootfs-versatile.cpio

I'm using this cross-compiler:
https://releases.linaro.org/components/toolchain/binaries/latest/arm-linux-gnueabihf/

This requires a reasonably recent QEMU which I extended with the
vblank emulation a while back. (If you don't have that the machine
hangs waiting for vblank for a long time in the DRM init.)

I get graphics on v4.18 and the commit preceeding this one.
It fails on v4.19-rc1.

Yours,
Linus Walleij