On Tue, Apr 23, 2019 at 02:58:01PM +0530, Manikanta Maddireddy wrote:
> Disable PCIe interrupts in runtime suspend to avoid executing irq handler
> and power off sequence in parallel.
>
> Following sequence triggers such scenario,
> - tegra_pcie_remove() triggers runtime suspend
> - pex_rst is asserted in runtime suspend
> - PRSNT_MAP bit field in RP_PRIV_MISC register changes from EP_PRSNT to
> EP_ABSNT
> - This is sensed by AFI and triggers "Slot present pin change" interrupt
> - tegra_pcie_isr() function accesses AFI register when runtime suspend
> is going through power off sequence
This sounds like more of a workaround than a proper solution. If the
above sequence crashes, it means that we have a bug somewhere in that
sequence. By the time the controller is runtime suspended, we should
have shut everything down already.
That said, from the looks of it, I think we may be able to fix this by
moving the pm_runtime_*() calls in tegra_pcie_remove() below the
tegra_pcie_put_resources(). At that point, nothing should be accessing
any registers anymore.
Thierry
>
> rmmod pci-tegra
> pci_generic_config_write32: 108 callbacks suppressed
> pci_bus 0002:00: 2-byte config write to 0002:00:02.0 offset 0x4c may corrupt adjacent RW1C bits
> pci_bus 0002:00: 2-byte config write to 0002:00:02.0 offset 0x9c may corrupt adjacent RW1C bits
> pci_bus 0002:00: 2-byte config write to 0002:00:02.0 offset 0x88 may corrupt adjacent RW1C bits
> pci_bus 0002:00: 2-byte config write to 0002:00:02.0 offset 0x90 may corrupt adjacent RW1C bits
> pci_bus 0002:00: 2-byte config write to 0002:00:02.0 offset 0x4 may corrupt adjacent RW1C bits
> igb 0002:04:00.1: removed PHC on enP2p4s0f1
> igb 0002:04:00.0: removed PHC on enP2p4s0f0
> pci_bus 0002:00: 2-byte config write to 0002:00:01.0 offset 0x4c may corrupt adjacent RW1C bits
> pci_bus 0002:00: 2-byte config write to 0002:00:01.0 offset 0x9c may corrupt adjacent RW1C bits
> pci_bus 0002:00: 2-byte config write to 0002:00:01.0 offset 0x88 may corrupt adjacent RW1C bits
> pci_bus 0002:00: 2-byte config write to 0002:00:01.0 offset 0x90 may corrupt adjacent RW1C bits
> pci_bus 0002:00: 2-byte config write to 0002:00:01.0 offset 0x4 may corrupt adjacent RW1C bits
> rcu: INFO: rcu_preempt self-detected stall on CPU
> SError Interrupt on CPU0, code 0xbf000002 -- SError
> CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 5.1.0-rc3-next-20190405-00027-gcd8110499e6f-dirty #42
> Hardware name: NVIDIA Jetson TX1 Developer Kit (DT)
> pstate: 20000085 (nzCv daIf -PAN -UAO)
> pc : tegra_pcie_isr+0x58/0x178 [pci_tegra]
> lr : tegra_pcie_isr+0x40/0x178 [pci_tegra]
> sp : ffff000010003da0
> x29: ffff000010003da0 x28: 0000000000000000
> x27: ffff8000f9e61000 x26: ffff000010fbf420
> x25: ffff000011427f93 x24: ffff8000fa600410
> x23: ffff00001129d000 x22: ffff00001129d000
> x21: ffff8000f18bf3c0 x20: 0000000000000070
> x19: 00000000ffffffff x18: 0000000000000000
> x17: 0000000000000000 x16: 0000000000000000
> x15: 0000000000000000 x14: ffff000008d40a48
> x13: ffff000008d40a30 x12: ffff000008d40a20
> x11: ffff000008d40a10 x10: ffff000008d40a00
> x9 : ffff000008d409e8 x8 : ffff000008d40ae8
> x7 : ffff000008d40ad0 x6 : ffff000010003e58
> x5 : ffff8000fac00248 x4 : 0000000000000000
> x3 : ffff000008d40b08 x2 : fffffffffffffff8
> x1 : ffff000008d3f4e8 x0 : 00000000ffffffff
> Kernel panic - not syncing: Asynchronous SError Interrupt
> CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 5.1.0-rc3-next-20190405-00027-gcd8110499e6f-dirty #42
> Hardware name: NVIDIA Jetson TX1 Developer Kit (DT)
> Call trace:
> dump_backtrace+0x0/0x158
> show_stack+0x14/0x20
> dump_stack+0xa8/0xcc
> panic+0x140/0x2f4
> nmi_panic+0x6c/0x70
> arm64_serror_panic+0x74/0x80
> __pte_error+0x0/0x28
> el1_error+0x84/0xf8
> tegra_pcie_isr+0x58/0x178 [pci_tegra]
> __handle_irq_event_percpu+0x70/0x198
> handle_irq_event_percpu+0x34/0x88
> handle_irq_event+0x48/0x78
> handle_fasteoi_irq+0xb4/0x190
> generic_handle_irq+0x24/0x38
> __handle_domain_irq+0x5c/0xb8
> gic_handle_irq+0x58/0xa8
> el1_irq+0xb8/0x180
> cpuidle_enter_state+0x138/0x358
> cpuidle_enter+0x18/0x20
> call_cpuidle+0x1c/0x48
> do_idle+0x230/0x2d0
> cpu_startup_entry+0x20/0x28
> rest_init+0xd4/0xe0
> arch_call_rest_init+0xc/0x14
> start_kernel+0x444/0x470
>
> Signed-off-by: Manikanta Maddireddy <mmaddireddy@xxxxxxxxxx>
> ---
> V2: This is new patch in V2
>
> drivers/pci/controller/pci-tegra.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
> index bb3c0af9c830..8c0ad038699d 100644
> --- a/drivers/pci/controller/pci-tegra.c
> +++ b/drivers/pci/controller/pci-tegra.c
> @@ -1622,6 +1622,18 @@ static int tegra_pcie_disable_msi(struct tegra_pcie *pcie)
> return 0;
> }
>
> +static void tegra_pcie_disable_interrupts(struct tegra_pcie *pcie)
> +{
> + u32 value;
> +
> + value = afi_readl(pcie, AFI_INTR_MASK);
> + value &= ~AFI_INTR_MASK_INT_MASK;
> + afi_writel(pcie, value, AFI_INTR_MASK);
> +
> + if (IS_ENABLED(CONFIG_PCI_MSI))
> + tegra_pcie_disable_msi(pcie);
> +}
> +
> static int tegra_pcie_get_xbar_config(struct tegra_pcie *pcie, u32 lanes,
> u32 *xbar)
> {
> @@ -2466,6 +2478,11 @@ static int __maybe_unused tegra_pcie_pm_suspend(struct device *dev)
> tegra_pcie_pme_turnoff(port);
>
> tegra_pcie_disable_ports(pcie);
> + /*
> + * disable interrupts to avoid executing irq handler in parallel
> + * to power off sequence.
> + */
> + tegra_pcie_disable_interrupts(pcie);
>
> if (pcie->soc->program_uphy) {
> err = tegra_pcie_phy_power_off(pcie);
> --
> 2.17.1
>
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