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Subject: Re: [PATCH 2/3] dmaengine: usb-dmac: Fix PM reference leak in
 usb_dmac_probe()
To:     Vinod Koul <vkoul@kernel.org>, Johan Hovold <johan@kernel.org>
CC:     <mcoquelin.stm32@gmail.com>, <alexandre.torgue@foss.st.com>,
        <michal.simek@xilinx.com>, <dmaengine@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-kernel@lists.infradead.org>, <yi.zhang@huawei.com>
References: <20210517081826.1564698-1-yukuai3@huawei.com>
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 <YLRfZfnuxc0+n/LN@vkoul-mobl.Dlink>
 <b6c340de-b0b5-6aad-94c0-03f062575b63@huawei.com>
 <YLSk/i6GmYWGEa9E@vkoul-mobl.Dlink> <YLSqD+9nZIWJpn+r@hovoldconsulting.com>
 <YLi4VGwzrat8wJHP@vkoul-mobl> <YL3TlDqe4KSr3ICl@hovoldconsulting.com>
 <YL3ynd1KiJoe9y6+@vkoul-mobl>
From:   "yukuai (C)" <yukuai3@huawei.com>
Message-ID: <c8fcdaa1-f053-47aa-2dad-521b8f34b8d1@huawei.com>
Date:   Mon, 5 Jul 2021 16:41:39 +0800
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Hi, Vinod

Are you still intrested in accepting this patch?

Thanks,
Yu Kuai

On 2021/06/07 18:19, Vinod Koul wrote:
> On 07-06-21, 10:06, Johan Hovold wrote:
>> On Thu, Jun 03, 2021 at 04:39:08PM +0530, Vinod Koul wrote:
>>> On 31-05-21, 11:19, Johan Hovold wrote:
>>>> On Mon, May 31, 2021 at 02:27:34PM +0530, Vinod Koul wrote:
>>>>> On 31-05-21, 14:11, yukuai (C) wrote:
>>>>>> On 2021/05/31 12:00, Vinod Koul wrote:
>>>>>>> On 17-05-21, 16:18, Yu Kuai wrote:
>>>>>>>> pm_runtime_get_sync will increment pm usage counter even it failed.
>>>>>>>> Forgetting to putting operation will result in reference leak here.
>>>>>>>> Fix it by replacing it with pm_runtime_resume_and_get to keep usage
>>>>>>>> counter balanced.
>>
>>>>> Yes the rumtime_pm is disabled on failure here and the count would have
>>>>> no consequence...
>>>>
>>>> You should still balance the PM usage counter as it isn't reset for
>>>> example when reloading the driver.
>>>
>>> Should I driver trust that on load PM usage counter is balanced and not
>>> to be reset..?
>>
>> Not sure what you're asking here. But a driver should never leave the PM
>> usage counter unbalanced.
> 
> Thinking about again, yes we should safely assume the counter is
> balanced when driver loads.. so unloading while balancing sounds better
> behaviour
> 
> Thanks
>