On 27/04/2020 16:38, Dmitry Osipenko wrote: > 27.04.2020 17:45, Dmitry Osipenko пишет: >> 27.04.2020 17:13, Dmitry Osipenko пишет: >>> 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@xxxxxxxxxx/ >>>> >>>> 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. >>> >> >> Oh, wait! There is already a warning there.. hmm. >> > > Aha, the disable depth for the I2C interrupt is 2 after > suspend_device_irq(), that's why there is no warning. > > This should catch the bug and trigger the warning: > > --- >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 --- > > 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 -- nvpublic
