On 04/25/2018 11:47 AM, Grygorii Strashko wrote: > > > On 04/25/2018 01:29 PM, Florian Fainelli wrote: >> 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. > > Sry, but it still required some clarification :( - poweroff calls > device_shutdown() which, in turn, should not call .suspend(), so > how have you got both .shutdown() and .suspend() callbacks called during > poweroff? Am I missing smth? You are missing me telling you the whole story, sorry I got confused, but you are absolutely right these are separate lists and on poweroff/shutdown only ->shutdown() is called. What I had missed in the report I was submitted was that there was a .shutdown() callback being added to gpio_keys.c, which of course, because it's an Android based project is not in the upstream Linux kernel. The problem does remain valid though AFAICT. Thanks Grygorii! -- 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
