Re: [PATCH -next] xtensa: Fix build error due to missing include file

[Guenter Roeck]

On 07/24/2016 08:18 AM, Rob Herring wrote:
> On Sun, Jul 24, 2016 at 9:20 AM, Max Filippov <jcmvbkbc@xxxxxxxxx> wrote:
> > On Sun, Jul 24, 2016 at 9:00 AM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> > > On 07/23/2016 05:45 PM, Max Filippov wrote:
> > > > On Sun, Jul 24, 2016 at 3:24 AM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> > > > > Commit 69d99e6c0d621f ("xtensa: Remove unnecessary of_platform_populate
> > > > > with default match table") dropped various include files from
> > > > > arch/xtensa/kernel/setup.c. This results in the following build error.
> > > > >
> > > > > arch/xtensa/kernel/setup.c: In function âxtensa_dt_io_areaâ:
> > > > > arch/xtensa/kernel/setup.c:213:2: error:
> > > > >           implicit declaration of function âof_read_ulongâ
> > > > >
> > > > > Fixes: 69d99e6c0d621f ("xtensa: Remove unnecessary of_platform_populate
> > > > > with default match table")
> > > > > Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> > > > > Cc: Rob Herring <robh@xxxxxxxxxx>
> > > > > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > > > > ---
> > > > > I would suggest to merge this patch into the commit causing the problem
> > > > > if possible.
> > > > >
> > > > >    arch/xtensa/kernel/setup.c | 1 +
> > > > >    1 file changed, 1 insertion(+)
> > > >
> > > >
> > > > Acked-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
> > >
> > > Heads up: xtensa images build after this patch, but the image that
> > > previously failed to build (generic_kc705_defconfig) doesn't boot,
> > > at least not with qemu. I don't know if this is caused by 69d99e6c0d621f
> > > or by some other patch.
> >
> > It seems to be booting, but serial console is non-functional.
> > With commit 69d99e6c0d621f ("xtensa: Remove unnecessary of_platform_populate
> > with default match table") I see the following message during boot:
> >
> > [    6.375284] of_serial fd050020.serial: clk or clock-frequency not defined
> >
> > Reverting that commit fixes serial console for me.
> > Any suggestions on what might go wrong?
>
> Probably the init order changed somehow and deferred probe is not
> supported correctly.

While the message is due to -EPROBE_DEFER (and there should really be no message
in this case), I suspect that the underlying problem is that of_clk_init() is
now called way too early, before the clock source is fully initialized.
Specifically, the call now happens before the message "clocksource: Switched
to clocksource ccount", which at least looks suspicious.

If I move of_clk_init() back into xtensa_device_probe(), to be called as
device_initcall(), everything is fine.

Guenter