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Subject: Re: [PATCH v1 04/10] bus: mhi: core: Use the IRQF_ONESHOT flag for
 the BHI interrupt line
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        Bhaumik Bhatt <bbhatt@codeaurora.org>
Cc:     linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org,
        linux-kernel@vger.kernel.org
References: <1600480955-16827-1-git-send-email-bbhatt@codeaurora.org>
 <1600480955-16827-5-git-send-email-bbhatt@codeaurora.org>
 <20201009155706.GE4810@Mani-XPS-13-9360>
From:   Jeffrey Hugo <jhugo@codeaurora.org>
Message-ID: <26de08b5-b477-c5b9-fdca-eb80bcf98561@codeaurora.org>
Date:   Fri, 9 Oct 2020 10:04:02 -0600
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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@codeaurora.org>
>> ---
>>   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.