Re: [PATCH v1 04/10] bus: mhi: core: Use the IRQF_ONESHOT flag for the BHI interrupt line

[Jeffrey Hugo]

On 10/9/2020 9:57 AM, Manivannan Sadhasivam wrote:
> On Fri, Sep 18, 2020 at 07:02:29PM -0700, Bhaumik Bhatt wrote:
> > Remove the IRQF_SHARED flag as it is not needed for the BHI interrupt
> > and replace it with IRQF_ONESHOT so that host can be sure that the
> > next BHI hard interrupt is triggered only when the threaded interrupt
> > handler has returned. This is to avoid any race conditions we may run
> > into if BHI interrupts fire one after another.
> >
> > Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
> > ---
> >   drivers/bus/mhi/core/init.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> > index ca32563..9ae4c19 100644
> > --- a/drivers/bus/mhi/core/init.c
> > +++ b/drivers/bus/mhi/core/init.c
> > @@ -167,7 +167,7 @@ int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
> >   	/* Setup BHI_INTVEC IRQ */
> >   	ret = request_threaded_irq(mhi_cntrl->irq[0], mhi_intvec_handler,
> >   				   mhi_intvec_threaded_handler,
> > -				   IRQF_SHARED | IRQF_NO_SUSPEND,
> > +				   IRQF_ONESHOT | IRQF_NO_SUSPEND,
>
> Jeff, I believe you're the one requested for shared irq during initial push.
> Are you okay with this?

Nope  :)

AIC100 has a single interrupt for BHI/MHI activity, so this needs to be 
shared.


--
Jeffrey Hugo
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.