Hi Santosh,
On 9/14/2011 7:22 PM, Shilimkar, Santosh wrote:
On Wednesday 14 September 2011 10:48 PM, Tony Lindgren wrote:
* Santosh<santosh.shilimkar@xxxxxx> [110914 09:40]:
On Wednesday 14 September 2011 10:38 PM, Tony Lindgren wrote:
* Santosh<santosh.shilimkar@xxxxxx> [110914 09:16]:
Thanks for the clarification. It seems to me the spec is most likely
wrong as we've had the GIC working for over two years now without
doing anything with the wakeup gen registers :)
It's working because CPU clockdomain are never put under HW
supervised mode and they are kept in force wakeup. Clock-domain
never idles on mainline code. PM series will put the clock-domains
under HW supervison as needed to achieve any low power states and
then all sorts of corner cases will come out.
But again the wakeup gen triggers only do something when hitting
idle. There should be no use for them during runtime, right?
You missed my point in the description. Clockdomain inactive
doesn't depend on idle or WFI execution. Under HW supervison
CPU clock domain can get into inactive when CPU is stalled and
waiting for a read response from slow interconnect.
I'm a little bit confused by that statement...
I'm wondering how the PRCM can gate the CPU/MPU clock and re-enable it
if the MPU is gated? What kind of event can wakeup the CPU in case of
CPU stalled?
The spec seems to indicate that wakeupgen is needed only if CPU are in
WFI. It is even written: "CPUx will change power state only when
StandbyWFI is asserted.". Even a WFE is not supposed to trigger a standby.
How can the CPU be inactive at clock domain level without a WFI?
Regards,
Benoit
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