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

From: Bhaumik Bhatt
Date: Mon Oct 12 2020 - 19:53:09 EST


On 2020-10-09 09:04, Jeffrey Hugo wrote:
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.

Did not account for this. Will drop this patch.

Thanks,
Bhaumik

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