From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Santosh) Date: Sun, 18 Sep 2011 14:17:05 +0530 Subject: [PATCH 23/25] OMAP4: PM: Add CPUidle support In-Reply-To: <87k498pejf.fsf@ti.com> References: <1315144466-9395-1-git-send-email-santosh.shilimkar@ti.com> <1315144466-9395-24-git-send-email-santosh.shilimkar@ti.com> <87k498pejf.fsf@ti.com> Message-ID: <4E75B009.5040308@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Friday 16 September 2011 11:15 PM, Kevin Hilman wrote: > Hi Santosh, > > Santosh Shilimkar writes: > >> Add OMAP4 CPUIDLE support. CPU1 is left with defualt idle and >> the low power state for it is managed via cpu-hotplug. >> >> This patch adds MPUSS low power states in cpuidle. >> >> C1 - CPU0 ON + CPU1 ON + MPU ON >> C2 - CPU0 OFF + CPU1 OFF + MPU CSWR >> C3 - CPU0 OFF + CPU1 OFF + MPU OSWR >> >> OMAP4460 onwards, MPUSS power domain doesn't support OFF state any more >> anymore just like CORE power domain. The deepest state supported is OSWr. >> Ofcourse when MPUSS and CORE PD transitions to OSWR along with device >> off mode, even the memory contemts are lost which is as good as >> the PD off state. >> >> On OMAP4 because of hardware constraints, no low power states are >> targeted when both CPUs are online and in SMP mode. The low power >> states are attempted only when secondary CPU gets offline to OFF >> through hotplug infrastructure. >> >> Thanks to Nicole Chalhoub for doing exhaustive >> C-state latency profiling. >> >> Signed-off-by: Rajendra Nayak >> Signed-off-by: Santosh Shilimkar >> Cc: Kevin Hilman > > A handful of minor comments below... > Will take care of them. Regards Santosh