pcie driver failed with errno -22 when request_irq().

[mcggoal]

hi, Experts

I have been long trapped on failure when loading altera pcie driver .ko module. I am trying to connect IMX8MQ with altera cyclone thru PCIE1.0/1 lane. My kernel is 4.9.88 and demo board is IMX8MQ evk and Terasic C5P, they are connected thru a M.2 to pcie adaptor.

The failure was reported when calling request_irq(), and return -22, which is EINVAL. Then I digged into the kernel and found failure was happened in irq_settings_can_request()  (/kernel/irq/manage.c),  which means the irq line is not allowed to request.

In the probe function of pcie driver, before request_irq(), I used pci_alloc_irq_vectors(pdev, 1,1, PCI_IRQ_ALL_TYPES) to enable one MSI, following is the debug log:

[ 72.098972] alt_up_pci init(), build at Jun 19 2020 08:57:28
[ 72.105806] alt_up_pci 0001:01:00.0: enabling device (0000 -> 0002)
[ 72.112302] pci_enable_device OK.
[ 72.115856] pci_request_regions OK.
[ 72.119611] pci_set_dma_mask OK.
[ 72.123050] pci_set_consistent_dma_mask OK.
[ 72.127508] alt_up_pci BAR2 initialized.
[ 72.131749] alt_up_pci BAR4 initialized.
[ 72.135848] PCIE BAR initialization OK.
[ 72.139904] alt_up_pci DMA0 initialized as type2.
[ 72.144890] alt_up_pci_dev_init OK.
[ 72.148590] pci_alloc_irq_vectors OK.
[ 72.152470] mydev->irq_line is 15!
[ 72.156082] Sanity-check passed!
[ 72.159431] irq_to_desc passed!
[ 72.162695] desc->status_use_accessors value is 68608
[ 72.168150] _IRQ_NOREQUEST value is 2048
[ 72.172274] _IRQ_PER_CPU_DEVID value is 131072
[ 72.176973] return val of request_irq is -22!
[ 72.181528] pci_request_irq() failed.
[ 72.185484] alt_up_pci_probe() failed with error: -22

The status_use_accessors value is 0x10c00, and irq_settings_can_request(), where this value and with _IRQ_NOREQEUST， the result is not zero, so EINVAL returned.

This is really puzzled for me. What I am dong wrong ? Attachment is pcie driver.

[mcggoal]

hi, Igor

Recompile the kernel is too time consuming for me, and my disk space is no allowed to do it.

Could you give some further suggestion based on the 4.9.88 kernel ?

[igorpadykov]

Hi Chenguang

4.9.88 kernel is very old and not more supported, recommended to

try latest kernels described on link

Embedded Linux for i.MX Applications Processors | NXP 

Best regards
igor
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