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<6f07e5c8-7916-7ea2-2fe7-d05f8f011471@nvidia.com> <77a31b2f-f525-ba9e-f1ae-2b474465bde4@gmail.com> <470b4de4-e98a-1bdc-049e-6259ad603507@nvidia.com>

<5fc71168-e4ac-11f6-dbf1-e80f4fae8d1a@gmail.com> <090241c4-e026-aea4-e1e9-a2a661b2c27e@gmail.com> <9a3d283c-d4ff-c55a-3ebf-4e08d35792ec@gmail.com> From: Jon Hunter Message-ID: Date: Tue, 28 Apr 2020 09:02:36 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <9a3d283c-d4ff-c55a-3ebf-4e08d35792ec@gmail.com> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL105.nvidia.com (172.20.187.12) To DRHQMAIL107.nvidia.com (10.27.9.16) Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: quoted-printable DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1588060949; bh=cs1RNBnpWaKHsxJ2zVYobPJtuZEqLrQg7l0V07UM/DQ=; h=X-PGP-Universal:Subject:To:CC:References:From:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:X-Originating-IP: X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=Ts7bsldutGOcpt00XXFlWXq8wow2vksLNocXXZrAJLO98TCQw9z/rcMoxs+9vBN87 NjhKpnRo8qppvvVIFHUCDA5xPoli9cSxGU+hW6c4eU/v0NYZH7HGMAiWJsJXTApuog THuUyDCgeCch+q2zPRUnuJT115hfJgNoN/e+XyTqzTMtIaweILW8qi8MEIEoeX0MG+ 9+SXJumCpx0F/A2xa+vOAcZjz+LnpB+Ww5gy+f/1WsMiipiSKsfftmSwPQ16iSg/bn fKfObu38ncJ0BE0i3vBBnIPY0NzNm/d/yR6zjrksXy9rgJkT1nYS6Kwwqb5Z8XkGDX T2YiaqTIhI39A== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/04/2020 16:38, Dmitry Osipenko wrote: > 27.04.2020 17:45, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >> 27.04.2020 17:13, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>> 27.04.2020 15:46, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>> 23.04.2020 13:56, Jon Hunter =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>>>>> So I think that part of the problem already existed prior to these >>>>>>> patches. Without your patches I see ... >>>>>>> >>>>>>> [ 59.543528] tegra-i2c 7000d000.i2c: i2c transfer timed out >>>>>>> [ 59.549036] vdd_sata,avdd_plle: failed to disable >>>>>>> [ 59.553778] Failed to disable avdd-plle: -110 >>>>>>> [ 59.558150] tegra-pcie 3000.pcie: failed to disable regulators: = -110 >>>>>> Does this I2C timeout happen with my patches? Could you please post = full >>>>>> logs of an older and the recent kernel versions? >>>>> I believe that it does, but I need to check. >>>>> >>>> >>>> Jon, could you please confirm that you're seeing those regulator-disab= le >>>> errors with my patch? I don't see those errors in yours original log [= 1]. >>>> >>>> [1] >>>> https://lore.kernel.org/lkml/1e259e22-c300-663a-e537-18d854e0f478@nvid= ia.com/ >>>> >>>> Again, could you please post the *full* logs? >>>> >>>> If regulator's disabling was "failing" before without my patch because >>>> of the I2C interrupt being force-disabled during of NOIRQ phase, and n= ow >>>> regulator's disabling succeeds with my patch because IRQ is manually >>>> handled after the timeout, then this could be bad. It means that >>>> regulator was actually getting disabled, but I2C driver was timing out >>>> because interrupt couldn't be handled in NOIRQ phase, which should >>>> result in a dead PCIe on a resume from suspend since regulator's core >>>> thinks that regulator is enabled (I2C said it failed to disable), whil= e >>>> it is actually disabled. >>>> >>>> Do you have anything plugged into the PCIe slot in yours testing farm? >>>> It wouldn't surprise me if the plugged card isn't functional after >>>> resume from suspend on a stable kernels. >>>> >>> >>> I actually now see that interrupt is not allowed to be enabled during >>> the NOIRQ phase: >>> >>> https://elixir.bootlin.com/linux/v5.7-rc3/source/kernel/irq/manage.c#L6= 40 >>> >>> it should be worthwhile to turn it into a WARN_ON. >>> >> >> Oh, wait! There is already a warning there.. hmm. >> >=20 > Aha, the disable depth for the I2C interrupt is 2 after > suspend_device_irq(), that's why there is no warning. >=20 > This should catch the bug and trigger the warning: >=20 > --- >8 --- > diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c > index 453a8a0f4804..fe25104d8b22 100644 > --- a/kernel/irq/manage.c > +++ b/kernel/irq/manage.c > @@ -653,6 +653,8 @@ void __enable_irq(struct irq_desc *desc) > break; > } > default: > + if (desc->istate & IRQS_SUSPENDED) > + goto err_out; > desc->depth--; > } > } > --- >8 --- >=20 > Jon could you please give it a try? Will this change produce a warning > for the I2C driver on a PCIe suspend for the v5.6 kernel? Yes I can test, but I still want to know why resume is currently broken. Jon --=20 nvpublic