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Date:   Fri, 17 Jul 2020 13:16:18 -0400
From:   Sasha Levin <sashal@kernel.org>
To:     Qais Yousef <qais.yousef@arm.com>
Cc:     Eugeniu Rosca <erosca@de.adit-jv.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Alan Stern <stern@rowland.harvard.edu>,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        linux-renesas-soc@vger.kernel.org, linux-pm@vger.kernel.org,
        Tony Prisk <linux@prisktech.co.nz>,
        Mathias Nyman <mathias.nyman@intel.com>,
        Oliver Neukum <oneukum@suse.de>,
        linux-arm-kernel@lists.infradead.org, linux-usb@vger.kernel.org,
        Andrew Gabbasov <andrew_gabbasov@mentor.com>,
        Dirk Behme <dirk.behme@de.bosch.com>,
        Eugeniu Rosca <roscaeugeniu@gmail.com>
Subject: Re: [PATCH 4.14 105/136] usb/ehci-platform: Set PM runtime as active
 on resume
Message-ID: <20200717171618.GQ2722994@sasha-vm>
References: <20200623195303.601828702@linuxfoundation.org>
 <20200623195308.955410923@linuxfoundation.org>
 <20200709070023.GA18414@lxhi-065.adit-jv.com>
 <20200717161639.37ptgbolborimcvs@e107158-lin.cambridge.arm.com>
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On Fri, Jul 17, 2020 at 05:17:23PM +0100, Qais Yousef wrote:
>Hi Eugeniu
>
>On 07/09/20 09:00, Eugeniu Rosca wrote:
>> Hello everyone,
>>
>> Cc: linux-renesas-soc
>> Cc: linux-pm
>
>[...]
>
>> After integrating v4.14.186 commit 5410d158ca2a50 ("usb/ehci-platform:
>> Set PM runtime as active on resume") into downstream v4.14.x, we started
>> to consistently experience below panic [1] on every second s2ram of
>> R-Car H3 Salvator-X Renesas reference board.
>>
>> After some investigations, we concluded the following:
>>  - the issue does not exist in vanilla v5.8-rc4+
>>  - [bisecting shows that] the panic on v4.14.186 is caused by the lack
>>    of v5.6-rc1 commit 987351e1ea7772 ("phy: core: Add consumer device
>>    link support"). Getting evidence for that is easy. Reverting
>>    987351e1ea7772 in vanilla leads to a similar backtrace [2].
>>
>> Questions:
>>  - Backporting 987351e1ea7772 ("phy: core: Add consumer device
>>    link support") to v4.14.187 looks challenging enough, so probably not
>>    worth it. Anybody to contradict this?
>>  - Assuming no plans to backport the missing mainline commit to v4.14.x,
>>    should the following three v4.14.186 commits be reverted on v4.14.x?
>>    * baef809ea497a4 ("usb/ohci-platform: Fix a warning when hibernating")
>>    * 9f33eff4958885 ("usb/xhci-plat: Set PM runtime as active on resume")
>>    * 5410d158ca2a50 ("usb/ehci-platform: Set PM runtime as active on resume")
>
>Thanks for investigating this.
>
>Alan, Greg, do you have any ideas?

I've reverted these 3 commits from 5.4 and earlier, thank you for
investigating this issue.

-- 
Thanks,
Sasha