Why INTB in PF100 regulator is always low

[yangao]

Hi,

I'm using iMX6 and PF100 regulator. The PF100 INTB is connected to iMX6 GPIO0. I found the INTB is always low, even there is not any interrupt is unmasked. What causes the INTB to be in low state?

Thanks,

Yan

[yangao]

Hi Igor,

How to "use" the interrupt? We connect the INTB to GPIO0 in iMX6. In the linux driver, we request IRQ and can receive the interrupt from the GPIO0. However, because no interrupts are unmasked, the interrupt from IRQ is not processed - this cause the IRQ to be disabled and a bunch of error message like below are generated:

[    6.394804] irq 160: nobody cared (try booting with the "irqpoll" option)
[    6.401622] CPU: 0 PID: 254 Comm: systemd-udevd Tainted: P           O 3.14.70-fslc+g33f49da #1
[    6.410367] [<80015f58>] (unwind_backtrace) from [<800124d4>] (show_stack+0x10/0x14)
[    6.418134] [<800124d4>] (show_stack) from [<80753174>] (dump_stack+0x84/0x98)
[    6.425383] [<80753174>] (dump_stack) from [<8006e360>] (__report_bad_irq+0x28/0xc4)
[    6.433144] [<8006e360>] (__report_bad_irq) from [<8006e760>] (note_interrupt+0x298/0x2e8)
[    6.441422] [<8006e760>] (note_interrupt) from [<8006c3bc>] (handle_irq_event_percpu+0x118/0x180)
[    6.450312] [<8006c3bc>] (handle_irq_event_percpu) from [<8006c460>] (handle_irq_event+0x3c/0x5c)
[    6.459198] [<8006c460>] (handle_irq_event) from [<8006eed4>] (handle_level_irq+0x98/0x104)
[    6.467564] [<8006eed4>] (handle_level_irq) from [<8006ba80>] (generic_handle_irq+0x2c/0x3c)
[    6.476022] [<8006ba80>] (generic_handle_irq) from [<802c82d0>] (mxc_gpio_irq_handler+0x3c/0x164)
[    6.484911] [<802c82d0>] (mxc_gpio_irq_handler) from [<802c8478>] (mx3_gpio_irq_handler+0x80/0xcc)
[    6.493885] [<802c8478>] (mx3_gpio_irq_handler) from [<8006ba80>] (generic_handle_irq+0x2c/0x3c)
[    6.502685] [<8006ba80>] (generic_handle_irq) from [<8000fa8c>] (handle_IRQ+0x40/0x90)
[    6.510617] [<8000fa8c>] (handle_IRQ) from [<800085ac>] (gic_handle_irq+0x2c/0x5c)
[    6.518200] [<800085ac>] (gic_handle_irq) from [<80013040>] (__irq_svc+0x40/0x70)
[    6.525691] Exception stack(0x9c5f3db8 to 0x9c5f3e00)
[    6.530752] 3da0:                                                       9a1ad4c8 80764740
[    6.538940] 3dc0: 00000000 00000000 9a1ad4c8 80764740 9c5f3f74 00020000 9c663bb8 9c5f3eb0
[    6.547130] 3de0: 9a1ad4c8 9a263cc0 00000000 9c5f3e00 800ff8c8 800ef8b8 60010013 ffffffff
[    6.555327] [<80013040>] (__irq_svc) from [<800ef8b8>] (d_set_d_op+0x74/0x114)
[    6.562568] [<800ef8b8>] (d_set_d_op) from [<800ff8c8>] (simple_lookup+0x54/0x5c)
[    6.570072] [<800ff8c8>] (simple_lookup) from [<800e4e6c>] (lookup_real+0x20/0x4c)
[    6.577662] [<800e4e6c>] (lookup_real) from [<800e92ac>] (do_last+0x87c/0xc78)
[    6.584900] [<800e92ac>] (do_last) from [<800e9760>] (path_openat+0xb8/0x67c)
[    6.592052] [<800e9760>] (path_openat) from [<800eabec>] (do_filp_open+0x2c/0x88)
[    6.599556] [<800eabec>] (do_filp_open) from [<800dc240>] (do_sys_open+0x104/0x1c8)
[    6.607230] [<800dc240>] (do_sys_open) from [<8000f1a0>] (ret_fast_syscall+0x0/0x38)
[    6.614981] handlers:
[    6.617267] [<8006c480>] irq_default_primary_handler threaded [<80311b50>] pfuze_irq_thread
[    6.625670] Disabling IRQ #160

Any ideas?

Thanks,

Yan

[igorpadykov]

Hi Yan

one can look on

linux - Understanding kernel message 'nobody cared (try booting with the "irqpoll" option)' - Stack ... 

Best regards
igor

[yangao]

Hi Igor,

Thanks for the link. I know the message is because that the IRQ is not processed by my handler(Because I did not unmask any interrupt thus no interrupt should be processed). The issue is why the interrupt comes any way(the INTB is low). I will talk with some HW guy to double check HW is correct.

Thanks,

Yan

[igorpadykov]

Hi Yan

could you try to reproduce issue on i.MX6DL Sabre SD board with

Demo Images from link i.MX Software | NXP 

Best regards
igor

[igorpadykov]

Hi Yan

seems pmic interrupts are not used, in general one can try to debug it using

sect.2.5.2 PMIC PF Regulator attached Linux Manual.

Best regards
igor
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