Re: [PATCH 3/6] clk: samsung: exynos4: Remove SRC_MASK_ISP gates

From: Tomasz Figa <t.figa@samsung.com>
To: Daniel Drake <drake@endlessm.com>
Cc: linux-samsung-soc <linux-samsung-soc@vger.kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, Kukjin Kim <kgene.kim@samsung.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Tomasz Figa <tomasz.figa@gmail.com>,
	Mike Turquette <mturquette@linaro.org>
Subject: Re: [PATCH 3/6] clk: samsung: exynos4: Remove SRC_MASK_ISP gates
Date: Wed, 25 Jun 2014 12:10:50 +0200	[thread overview]
Message-ID: <53AAA02A.1090601@samsung.com> (raw)
In-Reply-To: <CAD8Lp45a0kQocSFVeXGY99jE+Rx7PVwv6ZZKbE8iFp7G4=X12A@mail.gmail.com>

Hi Daniel,

On 25.06.2014 11:58, Daniel Drake wrote:
> Hi Tomasz,
> 
> On Tue, Jun 24, 2014 at 2:57 PM, Tomasz Figa <t.figa@samsung.com> wrote:
>> ISP special clocks have dedicated gating registers and so MUX SRC_MASK
>> register should not be used. This patch fixes the problem of
>> Exynos4x12-based boards freezing on system suspend, because those
>> mux outputs need not to be masked while suspending.
> 
> Not sure if you will be interested in this, as your plate must be
> pretty full already, and I am probably the first person to try
> suspend/resume on ODROID, but:
> 
> ODROID-U2 fails to suspend/resume. I am testing with rtcwake, trying
> to raise a wakeup alarm on the internal Exynos4412 RTC. For this,
> CONFIG_COMMON_CLK_MAX77686 must be disabled (otherwise it disables the
> upstream 32KHz clock source for the RTC), I also have
> CONFIG_RTC_DRV_MAX77686 disabled so that there is only one RTC to
> worry about.
> 
> Then:
>  rtcwake --utc -m mem -s 10 -v
> 
> Before this patch, it would totally hang after calling cpu_suspend()
> (checked with S3C_PMDBG) - not sure if it hangs before sleeping, or if
> it sleeps but simply fails to wake up.
> 
> With this patch, now it seems like the RTC alarm does wake up the
> system after the desired time, however it immediately goes back into
> uboot rather than resuming into Linux. So this patch does make some
> progress at least.
> 
> The power light is on at all times during these tests (not sure if
> that means anything, but I was wondering if it should go out when the
> system suspends).

As far as I'm aware of, all Exynos4412-based ODROIDs run secure
firmware, which needs special handling of suspend/resume. I already have
a series to address this, but there is one more issue that I'd like to
fix, until I send it. The patches should hit the ML this week, though.

Best regards,
Tomasz