On 04/25/2018 11:06 AM, Grygorii Strashko wrote: > > > On 04/24/2018 05:58 PM, Florian Fainelli wrote: >> Hi Linus, Rafael, all >> >> Our GPIO controller driver: gpio-brcmstb.c has a shutdown callback which >> gets invoked when the system is brought into poweroff aka S5. So far so >> good, except that we also wish to use gpio_keys.c as a possible wake-up >> source, so we may have a number of GPIO pins declared as gpio-keys that >> allow the system to wake-up from deep slumber. >> >> Recently we noticed that we could easily get into a state where >> gpio-brcmstb.c::brcmstb_gpio_shutdown() gets called first, and then >> gpio_keys.c::gpio_keys_suspend() gets called later, which is too late to >> have the enable_irq_wake() call do anything sensible since we have >> suspend its parent interrupt controller before. This is completely >> expected unfortunately because these two drivers are both platform >> device instances with no connection to one another except via Device >> Tree and the use of the GPIOLIB APIs. > > You can take a look at device_link_add() and Co. OK, though that requires a struct device references, so while I could certainly resolve the device_node -> struct device that corresponds to the GPIO provider , that poses a number of issues: - not all struct device_node have a corresponding struct device reference (e.g: clock providers, interrupt controllers, and possibly other custom drivers), though in this case, they most likely do have one - resolving a struct device associated with a struct device_node is often done in a "bus" specific way, e.g: of_find_device_by_node(), so if the GPIO provider is e.g: i2c_device, pci_device etc. etc. this might not work that easily I think this is what Dmitry just indicated in his email as well. > > But it's little bit unclear what exactly you have issue with: > - shutdown > - suspend > > above are different (at least as it was before) and gpio-brcmstb.c > brcmstb_gpio_shutdown() should not be called as part of suspend !? > may be you mean brcmstb_gpio_suspend? The issue exists with shutdown (through the use of "poweroff"), that is confirmed, but I cannot see how it does not exist with any suspend state as well, for the same reason that the ordering is not strictly enforced. -- Florian -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
