On Thu, Apr 22, 2010 at 3:31 PM, Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> wrote: > Mike Chan <mike@xxxxxxxxxxx> writes: > >> On Wed, Apr 21, 2010 at 5:07 PM, Kevin Hilman >> <khilman@xxxxxxxxxxxxxxxxxxx> wrote: >>> Mike Chan <mike@xxxxxxxxxxx> writes: >>> >>>> IO events can also come from GPIO modules, which reside in the PER domain. >>>> It is possible for the PER to enter RET while CORE is still in ON. >>>> If GPIO 2-6 are enabled for IO-pad wakeups, the PER domain will not >>>> wakeup in this case, unless we enable it. >>>> >>>> Signed-off-by: Mike Chan <mike@xxxxxxxxxxx> >>> >>> Hi Mike, >>> >>> I'm a little puzzled on this one. My understanding is that the IO pad >>> is only armed when CORE is in RET or OFF. >>> >> >> The issue we are seeing is when the device is active but idle, if CORE >> is ON and PER is in RET and the omap is sitting in swfi. If the user >> presses a keypad button, IO pad doesn't wake us out of idle. Setting a >> wakeup if PER or CORE goes into RET solve this. >> >>> I need to dig a little more in the TRM on this one to clarify. >>> >> >> I was looking at 4.11.2.2 I/O Wake-Up Mechanism (pg 421) >> > > Yeah, that's the right place. > > After a little more digging and asking around, this looks like a good > fix, but there's a minor problem with the implementation: > > In the section of the TRM you referenced the following sentence is > hiding: > > "Software must wait for the I/O daisy chain to complete before it > transitions the PER domain to a nonfunctional state." > > In the proposed patch, it's likely that PER could transition to > INACTIVE/RET/OFF before the IO wakeups are enabled. For example, if > nothing in PER is active except UART3, then PER will transition to an > idle state right after omap_uart_prepare_idle(2), which is before > the IO wakeups are currently enabled. > > To be perfectly safe, the IO wakeups should be enabled before PER is > allowed to transition. > Sounds good, I'll spin a v2 and send it out. -- Mike > Kevin > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
