From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [PATCH v2 1/2] i2c: tegra: Better handle case where CPU0 is busy for a long time Date: Mon, 27 Apr 2020 17:13:56 +0300 Message-ID: <5fc71168-e4ac-11f6-dbf1-e80f4fae8d1a@gmail.com> References: <20200324191217.1829-1-digetx@gmail.com> <20200324191217.1829-2-digetx@gmail.com> <1e259e22-c300-663a-e537-18d854e0f478@nvidia.com> <8cd085e1-f9fd-6ec0-9f7a-d5463f176a63@nvidia.com> <6f07e5c8-7916-7ea2-2fe7-d05f8f011471@nvidia.com> <77a31b2f-f525-ba9e-f1ae-2b474465bde4@gmail.com> <470b4de4-e98a-1bdc-049e-6259ad603507@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jon Hunter , Thierry Reding , Laxman Dewangan , Wolfram Sang , Manikanta Maddireddy , Vidya Sagar Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org 27.04.2020 15:46, Dmitry Osipenko пишет: > 23.04.2020 13:56, Jon Hunter пишет: >>>> 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-disable > 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-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org/ > > 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 now > 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), while > 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#L640 it should be worthwhile to turn it into a WARN_ON.