linux-kernel - Re: [PATCH v4 5/5] scsi: ufs: Do not free irq in suspend

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Message-ID: <0101016ea1842c0d-bbb3ea3d-c240-472f-87a6-d6b55edfb4a5-000000@us-west-2.amazonses.com>
Date:   Mon, 25 Nov 2019 07:43:44 +0000
From:   cang@...eaurora.org
To:     Avri Altman <Avri.Altman@....com>
Cc:     asutoshd@...eaurora.org, nguyenb@...eaurora.org,
        rnayak@...eaurora.org, linux-scsi@...r.kernel.org,
        kernel-team@...roid.com, saravanak@...gle.com, salyzyn@...gle.com,
        Alim Akhtar <alim.akhtar@...sung.com>,
        Pedro Sousa <pedrom.sousa@...opsys.com>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Stanley Chu <stanley.chu@...iatek.com>,
        Bean Huo <beanhuo@...ron.com>,
        Tomas Winkler <tomas.winkler@...el.com>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4 5/5] scsi: ufs: Do not free irq in suspend

On 2019-11-20 23:36, Avri Altman wrote:
>> 
>> If PM QoS is enabled and we set request type to PM_QOS_REQ_AFFINE_IRQ
>> then freeing up the irq makes the free_irq() print out warning with 
>> call stack.
>> We don't really need to free up irq during suspend, disabling it 
>> during suspend
>> and reenabling it during resume should be good enough.
>> 
>> Signed-off-by: Can Guo <cang@...eaurora.org>
> Your approach seems reasonable,
> However I failed to locate in the kernel PM_QOS_REQ_AFFINE_IRQ,
> Just in codeaurora.
> 
> Is the WARN_ON in free_irq still applies?
> 
> Thanks,
> Avri

Hi Avri,

Thanks for pointing. It seems PM_QOS_REQ_AFFINE_IRQ is not present
on upstream yet. But this change is still applicable.
How about changing the commit message to below?

"Since ufshcd irq resource is allocated with the device resource
management aware IRQ request implementation, we don't really need
to free up irq during suspend, disabling it during suspend and
reenabling it during resume should be good enough."

Thanks,
Can Guo