Re: [PATCH 15/20] ARM/hw_breakpoint: Convert to hotplug state machine

From: Linus Walleij <linus.walleij@linaro.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	rt@linuxtronix.de,
	Russell King - ARM Linux <linux@armlinux.org.uk>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Stephen Boyd <sboyd@codeaurora.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 15/20] ARM/hw_breakpoint: Convert to hotplug state machine
Date: Thu, 5 Jan 2017 16:26:45 +0100	[thread overview]
Message-ID: <CACRpkdYCG71AUe9iBdV+2t_LNFSzYO18vM=-pa=jWDTT53FnwA@mail.gmail.com> (raw)
In-Reply-To: <20170104135644.GA29212@leverpostej>

On Wed, Jan 4, 2017 at 2:56 PM, Mark Rutland <mark.rutland@arm.com> wrote:

> I've just reproduced this locally on my dragonboard APQ8060.

Sweet!

> It looks like the write_wb_reg() call that's exploding is from
> get_max_wp_len(), which we call immediately after registering the
> dbg_reset_online callback. Clearing DBGPRSR.SPD before the write_wb_reg() hides
> the problem, so I suspect we're seeing the issue I mentioned above -- it just
> so happens that we go idle in a new place.
>
> The below hack allows boot to continue, but is not a real fix. I'm not
> immediately sure what to do.

Me neither. But Will's suggestion to simply blacklist this chip might be
best.

> Linus, I wasn't able to get ethernet working. Do I need anything on top
> of v4.10-rc2 && multi_v7_defconfig?

I haven't tried it with multi_v7 but I should probably try that and patch
up the defconfigs, those are probably the root of the problem.

I do this on top of qcom_defconfig:

scripts/config --file .config \
        --enable QCOM_EBI2 \
        --enable ETHERNET \
        --enable NET_VENDOR_SMSC \
        --enable SMSC911X

Maybe you are missing the EBI2 config?

Yours,
Linus Walleij