Hello Dmitry. Please find replies inline. On Sun, 2011-12-04 at 00:50 -0800, Dmitry Torokhov wrote: > Hi Rakesh, > > On Thu, Dec 01, 2011 at 01:09:59PM -0800, Rakesh Iyer wrote: > > Hello Dmitry. > > > > Sorry for the wrap issue, my Outlook does not seem to obey the settings. > > > > I wanted to explain the tegra system resume path implementation so I can justify > > why I am doing this complicated fix and why I feel it will guarantee the resume > > is due to keypress. > > > > The tegra wake resume code is registered as a syscore ops. > > When the system is resumed due to a wake event, the suspend_enter (after wakeup) > > routine will invoke the tegra syscoreops_resume method and that routine will propagate > > the wake event to the individual ISR's through genirq. > > If kbc was wake source, kbc_isr will be invoked in this execution path. > > > > If system is resumed due to other reason, the tegra_syscoreops_resume code will not > > find the event. > > Consider the following sequence: > > 1. Something other than keyboard generates wakeup event > 2. It's IRQ fires up and gets serviced At this point syscoreops_resume has finished all its wakeup processing. > 3. System starts resuming devices > 4. User presses a key on the keypad while it is still suspended _and_ > registered as a wakeup source This will have no impact on the system and keypad ISR will not be invoked. > 5. Keypad's ISR runs as well and you decide that KEY_POWER should be > reported even though keypad wasn't the real reason the system > woke up. The interrupt line we use to detect wakeup processing is the keypress interrupt which is disabled and will never cause the ISR invocation from a device interrupt(i.e. the PIC). In other words KBC isr gets invoked for 2 reasons a) FIFO interrupt is generated, which will not happen as long as scanning logic is disabled until kbc_resume executes. b) The syscoreops_resume codepath calls into the ISR after finding KBC was a wakesource. If this happens it will happen only when the kernel resumes from its suspend code path. > > Is this scenario not possible? > > Thanks. > With that being the case do you think the fix makes sense? Regards Rakesh -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
