Am Freitag, den 24.07.2015, 13:29 +0800 schrieb Kevin Hao: > The cascade handler must run in hard interrupt context, otherwise > it will cause the following kernel warning if we force threading > of all the interrupt handlers via kernel command parameter > "threadirqs": > [ INFO: inconsistent lock state ] > 4.2.0-rc3-next-20150723 #28 Not tainted > --------------------------------- > inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. > irq/21-mx6-pcie/62 [HC0[0]:SC0[2]:HE1:SE0] takes: > (&irq_desc_lock_class){?.-...}, at: [<80078d94>] handle_simple_irq+0x1c/0xc0 > {IN-HARDIRQ-W} state was registered at: > [<8006aa70>] lock_acquire+0x74/0x94 > [<807acc6c>] _raw_spin_lock+0x34/0x44 > [<8007900c>] handle_fasteoi_irq+0x20/0x1b8 > [<80075720>] generic_handle_irq+0x28/0x38 > [<80075864>] __handle_domain_irq+0x6c/0xe0 > [<80009558>] gic_handle_irq+0x28/0x68 > [<80013b64>] __irq_svc+0x44/0x5c > [<807ad400>] _raw_spin_unlock_irq+0x30/0x34 > [<8004cffc>] finish_task_switch+0xc0/0x218 > [<807a7a10>] __schedule+0x248/0x6e0 > [<807a7fac>] schedule+0x38/0x9c > [<807a8240>] schedule_preempt_disabled+0x10/0x14 > [<80063f8c>] cpu_startup_entry+0xfc/0x1f8 > [<8079f640>] rest_init+0x130/0x16c > [<80a55ca4>] start_kernel+0x374/0x3e8 > [<1000807c>] 0x1000807c > irq event stamp: 16 > hardirqs last enabled at (15): [<807ad3fc>] _raw_spin_unlock_irq+0x2c/0x34 > hardirqs last disabled at (14): [<807acd80>] _raw_spin_lock_irq+0x20/0x58 > softirqs last enabled at (0): [<800283d8>] copy_process.isra.58+0x3bc/0x1504 > softirqs last disabled at (16): [<80076f08>] irq_forced_thread_fn+0x0/0x68 > > other info that might help us debug this: > Possible unsafe locking scenario: > > CPU0 > ---- > lock(&irq_desc_lock_class); > <Interrupt> > lock(&irq_desc_lock_class); > > *** DEADLOCK *** > > no locks held by irq/21-mx6-pcie/62. > > stack backtrace: > CPU: 0 PID: 62 Comm: irq/21-mx6-pcie Not tainted 4.2.0-rc3-next-20150723 #28 > Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) > Backtrace: > [<80012dc4>] (dump_backtrace) from [<80012f64>] (show_stack+0x18/0x1c) > r6:be3eeb78 r5:00000000 r4:00000000 r3:00000000 > [<80012f4c>] (show_stack) from [<807a4b50>] (dump_stack+0x80/0x9c) > [<807a4ad0>] (dump_stack) from [<807a2efc>] (print_usage_bug+0x270/0x2e4) > r5:be3ee780 r4:80c579ec > [<807a2c8c>] (print_usage_bug) from [<8006874c>] (mark_lock+0x5b4/0x6e0) > r10:80c579ec r9:800678e0 r8:be3ee780 r7:00000000 r6:80c579ec r5:be3eeb78 > r4:00000002 > [<80068198>] (mark_lock) from [<80068f70>] (__lock_acquire+0x6f8/0x1e20) > r10:00000001 r9:be3eeb78 r8:be3ee780 r7:00000008 r6:000003f8 r5:be3ee780 > r4:00000000 > [<80068878>] (__lock_acquire) from [<8006aa70>] (lock_acquire+0x74/0x94) > r10:00000001 r9:00000001 r8:00000000 r7:00000001 r6:00000001 r5:60030013 > r4:00000000 > [<8006a9fc>] (lock_acquire) from [<807acc6c>] (_raw_spin_lock+0x34/0x44) > r6:0000012c r5:00000001 r4:be1f4d64 > [<807acc38>] (_raw_spin_lock) from [<80078d94>] (handle_simple_irq+0x1c/0xc0) > r5:be1f4d64 r4:be1f4d00 > [<80078d78>] (handle_simple_irq) from [<80075720>] (generic_handle_irq+0x28/0x38) > r5:be28ee20 r4:0000012c > [<800756f8>] (generic_handle_irq) from [<80321914>] (dw_handle_msi_irq+0x68/0x90) > r4:00000001 r3:00000002 > [<803218ac>] (dw_handle_msi_irq) from [<8032265c>] (imx6_pcie_msi_handler+0x14/0x18) > r7:80076f08 r6:be39efc0 r5:be154000 r4:be39efc0 > [<80322648>] (imx6_pcie_msi_handler) from [<80076f38>] (irq_forced_thread_fn+0x30/0x68) > [<80076f08>] (irq_forced_thread_fn) from [<80076cb4>] (irq_thread+0x14c/0x19c) > r6:be39efc0 r5:be154000 r4:be39efe0 r3:00000004 > [<80076b68>] (irq_thread) from [<80047f80>] (kthread+0xdc/0xf8) > r10:00000000 r9:00000000 r8:00000000 r7:80076b68 r6:be39efc0 r5:be3a1000 > r4:00000000 > [<80047ea4>] (kthread) from [<8000fa38>] (ret_from_fork+0x14/0x3c) > r7:00000000 r6:00000000 r5:80047ea4 r4:be3a1000 > > Signed-off-by: Kevin Hao <haokexin@xxxxxxxxx> Reviewed-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx> > --- > drivers/pci/host/pci-imx6.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c > index 233a196c6e66..fd5eb2e34fc0 100644 > --- a/drivers/pci/host/pci-imx6.c > +++ b/drivers/pci/host/pci-imx6.c > @@ -544,7 +544,8 @@ static int __init imx6_add_pcie_port(struct pcie_port *pp, > > ret = devm_request_irq(&pdev->dev, pp->msi_irq, > imx6_pcie_msi_handler, > - IRQF_SHARED, "mx6-pcie-msi", pp); > + IRQF_SHARED | IRQF_NO_THREAD, > + "mx6-pcie-msi", pp); > if (ret) { > dev_err(&pdev->dev, "failed to request MSI irq\n"); > return -ENODEV; -- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html