Re: HiKey boot hangs with Linus' HEAD due to coresight dts changes?

[Leo Yan]

On Thu, Nov 16, 2017 at 08:15:15PM -0800, John Stultz wrote:
> On Thu, Nov 16, 2017 at 6:06 PM, Leo Yan <leo.yan@xxxxxxxxxx> wrote:
> > Hi John,
> >
> > On Thu, Nov 16, 2017 at 05:58:54PM -0800, John Stultz wrote:
> >> On Thu, Nov 16, 2017 at 5:54 PM, John Stultz <john.stultz@xxxxxxxxxx> wrote:
> >> > Testing with Linus' HEAD today on the HiKey board, I started seeing boot hangs:
> >> > ...
> >> >
> >> > [    0.677971] Serial: AMBA PL011 UART driver
> >> > [    0.694299] pstore: using zlib compression
> >> > [    0.698830] console [pstore-1] enabled
> >> > [    0.702623] pstore: Registered ramoops as persistent store backend
> >> > [    0.708880] ramoops: attached 0x100000@0x21f00000, ecc: 0/0
> >> > [    0.715847] f8015000.uart: ttyAMA0 at MMIO 0xf8015000 (irq = 7,
> >> > base_baud = 0) is a PL011 rev2
> >> > [    0.725011] uart-pl011 f7111000.uart: could not find pctldev for
> >> > node /soc/pinmux@f7010000/uart1_pmx_func, deferring probe
> >> > [    0.736375] uart-pl011 f7112000.uart: could not find pctldev for
> >> > node /soc/pinmux@f7010000/uart2_pmx_func, deferring probe
> >> > <hangs here>
> >> >
> >> > Bisecting this down, points to:
> >> >   0b79842775fa ("arm64: dts: hi6220: add coresight dt nodes")
> >> >
> >> > Reverting this patch makes things work again.
> >> >
> >> > Any ideas as to what might be wrong?
> >> >
> >> > Please let me know if I can test any fixes or provide any additional info.
> >>
> >> If its helpful, the full tree I'm using (with the problematic patch
> >> reverted - as well as a few other needed fixups for recent
> >> regressions) is here:
> >>    https://git.linaro.org/people/john.stultz/android-dev.git
> >> dev/hikey-mainline-WIP
> >>
> >> I'm using the "hikey_defconfig" added in the patchset to build with.
> >
> > Could you check if below patch has been merged into your code base?
> >
> > From f71a1da256962fbaac48ce0ec01600a1a43f42a1 Mon Sep 17 00:00:00 2001
> > From: Leo Yan <leo.yan@xxxxxxxxxx>
> > Date: Thu, 31 Aug 2017 20:36:47 +0800
> > Subject: [PATCH] clk: hi6220: mark clock cs_atb_syspll as critical
> >
> > Clock cs_atb_syspll is pll used for coresight trace bus; when clock
> > cs_atb_syspll is disabled and operates its child clock node cs_atb
> > results in system hang. So mark clock cs_atb_syspll as critical to
> > keep it enabled.
> 
> No I don't have this in yet. Hopefully its queued up already, and it
> just landed out of order?

Yeah, I checked this patch is in linux-next already; I expect this
patch should go with coresight DT binding patch together for 4.15-rcX,
but seems coresight DT binding patch has been merged ahead.

> Adding this patch does seem to resolve the issue.

Thanks for testing.

Thanks,
Leo Yan