Hi Matthias,
On Freitag, 8. Oktober 2021 13:49:25 CEST Matthias Brugger wrote:
> On 05/10/2021 22:28, Luca Weiss wrote:
> > Add rudimentary support for the Fairphone 1, based on MT6589 to boot to
> > UART console.
> >
> > The recently added SMP support needs to be disabled for this board as
> > the kernel panics executing /init with it, even though the CPUs seem to
> > start up fine - maybe a stability issue.
> >
> > [ 0.072010] smp: Bringing up secondary CPUs ...
> > [ 0.131888] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001
> > [ 0.191889] CPU2: thread -1, cpu 2, socket 0, mpidr 80000002
> > [ 0.251890] CPU3: thread -1, cpu 3, socket 0, mpidr 80000003
> > [ 0.251982] smp: Brought up 1 node, 4 CPUs
> > [ 0.254745] SMP: Total of 4 processors activated (7982.28 BogoMIPS).
> > [ 0.255582] CPU: All CPU(s) started in SVC mode.
> >
> > [ 0.472039] Run /init as init process
> > [ 0.473317] Kernel panic - not syncing: Attempted to kill init!
> > exitcode=0x00000004
> Would be nice to find out why. Did you tried to boot the system with
> enable-method set but with bringing up just one or two cpus?
Answered further down.
>
> > Signed-off-by: Luca Weiss <luca@xxxxxxxxx>
> > ---
> >
> > arch/arm/boot/dts/Makefile | 1 +
> > arch/arm/boot/dts/mt6589-fairphone-fp1.dts | 30 ++++++++++++++++++++++
> > 2 files changed, 31 insertions(+)
> > create mode 100644 arch/arm/boot/dts/mt6589-fairphone-fp1.dts
> >
> > diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
> > index 7e0934180724..24f402db2613 100644
> > --- a/arch/arm/boot/dts/Makefile
> > +++ b/arch/arm/boot/dts/Makefile
> > @@ -1437,6 +1437,7 @@ dtb-$(CONFIG_ARCH_MEDIATEK) += \
> >
> > mt2701-evb.dtb \
> > mt6580-evbp1.dtb \
> > mt6589-aquaris5.dtb \
> >
> > + mt6589-fairphone-fp1.dtb \
> >
> > mt6592-evb.dtb \
> > mt7623a-rfb-emmc.dtb \
> > mt7623a-rfb-nand.dtb \
> >
> > diff --git a/arch/arm/boot/dts/mt6589-fairphone-fp1.dts
> > b/arch/arm/boot/dts/mt6589-fairphone-fp1.dts new file mode 100644
> > index 000000000000..32c14ecf2244
> > --- /dev/null
> > +++ b/arch/arm/boot/dts/mt6589-fairphone-fp1.dts
> > @@ -0,0 +1,30 @@
> > +// SPDX-License-Identifier: BSD-3-Clause
> > +/*
> > + * Copyright (c) 2021, Luca Weiss <luca@xxxxxxxxx>
> > + */
> > +
> > +/dts-v1/;
> > +#include "mt6589.dtsi"
> > +
> > +/ {
> > + model = "Fairphone 1";
> > + compatible = "fairphone,fp1", "mediatek,mt6589";
> > +
> > + chosen {
> > + stdout-path = &uart3;
> > + };
> > +
> > + cpus {
>
> I'd expected "&cpus" why can we overwrite delete the node property like this
> here?
Both results in the same, dtc just merges everything together, so as long as
the node name is identical, it works.
Also I cannot use &cpus because cpus in mt6589.dtsi doesn't have a label set.
Regarding SMP:
I have tried setting maxcpus=2 in cmdline and that still makes the kernel
panic. With maxcpus=1 and leaving the deleting out of the dts the kernel is
stable and works properly.
So I think it's better to leave this out of the dts and keep maxcpus=1 in
cmdline (until this gets fixed).
I've also heard from the person adding enable-method to mt6589.dtsi that it
still works on their board, so something's different, maybe a different SoC
revision, different bootloader behavior or whatever.
If that's fine with you, I'll send a v2 with that fixed.
> > + /* SMP is not stable on this board, makes the kernel
panic */
> > + /delete-property/ enable-method;
> > + };
> > +
> > + memory {
Also I was told off-list that this should be called memory@80000000 because of
the reg, will fix in v2.
Regards
Luca
> > + device_type = "memory";
> > + reg = <0x80000000 0x40000000>;
> > + };
> > +};
> > +
> > +&uart3 {
> > + status = "okay";
> > +};
