Messages in this thread | | | Subject | Re: [PATCH V2 1/1] soc: qcom: smp2p: Add wakeup capability to SMP2P IRQ | From | Deepak Kumar Singh <> | Date | Mon, 13 Sep 2021 23:15:19 +0530 |
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On 8/17/2021 1:53 AM, Stephen Boyd wrote: > Quoting Deepak Kumar Singh (2021-08-16 03:05:35) >> Remote susbsystems notify fatal crash throught smp2p interrupt. >> When modem/wifi crashes it can cause soc to come out of low power state >> and may not allow again to enter in low power state until crash is handled. >> >> Mark smp2p interrupt wakeup capable so that interrupt handler is executed >> and remote susbsystem crash can be handled in system resume path. >> >> Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org> >> --- >> drivers/soc/qcom/smp2p.c | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/drivers/soc/qcom/smp2p.c b/drivers/soc/qcom/smp2p.c >> index 2df4883..646848b 100644 >> --- a/drivers/soc/qcom/smp2p.c >> +++ b/drivers/soc/qcom/smp2p.c >> @@ -18,6 +18,7 @@ >> #include <linux/soc/qcom/smem.h> >> #include <linux/soc/qcom/smem_state.h> >> #include <linux/spinlock.h> >> +#include <linux/pm_wakeirq.h> > Please sort alphabetically by include name, 'p' before 's'. > >> /* >> * The Shared Memory Point to Point (SMP2P) protocol facilitates communication >> @@ -538,9 +539,20 @@ static int qcom_smp2p_probe(struct platform_device *pdev) >> goto unwind_interfaces; >> } >> >> + /* Setup smp2p interrupt as wakeup source */ > This comment is bad. Please don't reiterate what the code is doing. > Instead, write something like > > /* > * Treat remoteproc crashes as wakeups by default so we handle > * them sooner rather than along with the next wakeup (e.g. > * power button). This avoids leaving the system in a shallower > * suspend power state if a remoteproc crashes during suspend, > * but requires userspace to actively suspend the device after > * handling the crash, or CONFIG_PM_AUTOSLEEP to be true. > */ > >> + ret = device_init_wakeup(&pdev->dev, true); > I still wonder if it's better to leave this off by default and only > enable it if the kernel is using autosuspend (PM_AUTOSLEEP). Then > userspace is responsible to decide if it can handle the wakeup with the > screen off, reload the remoteproc, and go back to suspend if it isn't > using autosuspend.
Seems like not all targets use PM_AUTOSLEEP feature, even those targets may require wakeup to handle
modem crash so that important modem events are not missed. I think we can keep wake up as default behavior
and let the user space disable it through sysfs if it doesn't want it as wake up source.
>> + if (ret) >> + goto unwind_interfaces; >> +
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