From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Wed, 8 Sep 2010 16:12:32 +0100 Subject: [PATCH 48/74] GIC: Added dummy handlers for Power Management Suspend Resume In-Reply-To: <4C84D6B3.80104@st.com> References: <47425e7be671c44d949b1804436b5c301d20d793.1283161023.git.viresh.kumar@st.com> <20100902102323.GP26319@n2100.arm.linux.org.uk> <4C809486.2070308@st.com> <20100903073421.GF26319@n2100.arm.linux.org.uk> <4C84D6B3.80104@st.com> Message-ID: <20100908151232.GD32659@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Sep 06, 2010 at 05:25:31PM +0530, deepaksi wrote: > On 9/3/2010 1:04 PM, Russell King - ARM Linux wrote: > > So how are wakeup sources configured if this callback does nothing? > > . > > In most of the architectures that I could refer across(including SPEAr > family -SPEAr13xx), > have a separate power management unit(PMU) which is required to be > configured to define the wake > up sources. The PMU takes care of waking up the system from sleep, as > and when the wake up > interrupts are triggered. This routing is independent of GIC, and hence > the handling was not added. > > Contrary to that, in some of our hardware architecture using VIC > (including SPEAr 3xx/6xx), there > was no explicit PMU, and the wake up trigger was exclusively done > through VIC, and hence the VIC > call backs had the necessary implementation. What I read into this is that you're using enable_irq_wake() in your drivers _and_ another mechanism to configure what wakes up the system via the PMU - maybe with drivers explicitly calling out to the PMU to achieve this? This sounds a little haphazard, especially from the drivers point of view. Surely there's a more sensible solution to this rather than adding do-nothing irq_wake support?