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?
Note. Suspend and shutdown uses different dev lists:
- shutdown uses kset
- suspend uses dpm_list
--
regards,
-grygorii
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