From: s.nawrocki@samsung.com (Sylwester Nawrocki)
Date: Wed, 01 Oct 2014 18:36:47 +0200
Subject: [PATCH v2 1/4] PM / Domains: Remove pm_genpd_dev_need_restore()
 API
In-Reply-To: <1412174494-15346-2-git-send-email-ulf.hansson@linaro.org>
References: <1412174494-15346-1-git-send-email-ulf.hansson@linaro.org>
 <1412174494-15346-2-git-send-email-ulf.hansson@linaro.org>
Message-ID: <542C2D9F.8060005@samsung.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 01/10/14 16:41, Ulf Hansson wrote:
> There are currently no users of this API, let's remove it.

The sad fact is that removal of pm_genpd_dev_need_restore() calls
from arch/arm/mach-exynos/pm_domains.c introduces regressions in
multiple exynos drivers (I'm sure it breaks media drivers).
I think before doing such changes all relevant drivers should be
updated first. I need to take a closer look again, but it seems
after dropping the pm_genpd_dev_need_restore() calls, client
driver's runtime_resume() callback is not being called in response
to first pm_runtime_get(_sync) call, even if a device is runtime
pm active.

More details can be found in commit ebc35c726298ba3fdebba316a
'ARM: EXYNOS: register devices in 'need_restore' state for pm_domains'.

The above only happens when devices are added to an inactive power
domain, then I guess patch 2/4 is also an attempt to address this
issue ?

--
Thanks,
Sylwester