Re: [PATCH V1 1/1] soc: qcom: smp2p: Add wakeup capability to SMP2P IRQ

[Sibi Sankar <sibis@codeaurora.org>]

On 2021-08-09 23:28, Stephen Boyd wrote:
> Quoting Deepak Kumar Singh (2021-08-09 04:05:08)
>> 
>> On 8/6/2021 1:10 AM, Stephen Boyd wrote:
>> > Quoting Deepak Kumar Singh (2021-08-05 09:17:33)
>> >> Some use cases require SMP2P interrupts to wake up the host
>> >> from suspend.
>> > Please elaborate on this point so we understand what sort of scenarios
>> > want to wakeup from suspend.
>> 
>> Once such scenario is where WiFi/modem crashes and notifies crash to
>> local host through smp2p
>> 
>> if local host is in suspend it should wake up to handle the crash and
>> reboot the WiFi/modem.
> 
> Does anything go wrong if the firmware crashes during suspend and the
> local host doesn't handle it until it wakes for some other reason? I'd
> like to understand if the crash handling can be delayed/combined with
> another wakeup.

If the modem firmware crashes
during suspend, the system comes
out of xo-shutdown and AFAIK stays
there until we handle the interrupt.

> 
>> 
>> >> Mark smp2p interrupt as wakeup capable to abort
>> >> the suspend.
>> >>
>> >> Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
>> >> ---
>> >>   drivers/soc/qcom/smp2p.c | 11 +++++++++++
>> >>   1 file changed, 11 insertions(+)
>> >>
>> >> diff --git a/drivers/soc/qcom/smp2p.c b/drivers/soc/qcom/smp2p.c
>> >> index 2df4883..f8659b0 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>
>> >>
>> >>   /*
>> >>    * The Shared Memory Point to Point (SMP2P) protocol facilitates communication
>> >> @@ -538,9 +539,19 @@ static int qcom_smp2p_probe(struct platform_device *pdev)
>> >>                  goto unwind_interfaces;
>> >>          }
>> >>
>> >> +       ret = device_init_wakeup(&pdev->dev, true);
>> > Is smp2p supposed to wake up the device by default? If not, then this
>> > should be device_set_wakeup_capable() instead so that userspace can
>> > decide if it wants to get the wakeup.
>> yes, we want smp2p to be wake up capable by default.
> 
> Why?

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