Subject: Re: [patch V3 00/35] genirq/msi, PCI/MSI: Spring cleaning - Part 2

From: Thomas Gleixner <[email-masked]>
Date: Tue, 14 Dec 2021 17:36:00 +0100

On Tue, Dec 14 2021 at 10:22, Nishanth Menon wrote:
> On 10:41-20211214, Thomas Gleixner wrote:
> Agreed that the warning is fine, the null pointer exception that follows
> [1] [2] it however does'nt look right and it can be trivially fixed with the
> following fixup for ee90787487bc ("genirq/msi: Provide
> msi_device_populate/destroy_sysfs()") below, with that the log looks
> like [3] - the warn is good, the null pointer exception and resultant
> crash could be avoided (not saying this is the best solution):

Aaargh.

[   13.478122] Call trace:
[   13.509042]  msi_device_destroy_sysfs+0x18/0x88
[   13.509058]  msi_domain_free_irqs+0x34/0x58
[   13.509064]  pci_msi_teardown_msi_irqs+0x30/0x3c
[   13.509072]  free_msi_irqs+0x78/0xd4
[   13.509077]  pci_disable_msix+0x138/0x164
[   13.529930]  pcim_release+0x70/0x238
[   13.529942]  devres_release_all+0x9c/0xfc
[   13.529951]  device_release_driver_internal+0x1a0/0x244
[   13.542725]  device_release_driver+0x18/0x24
[   13.542741]  iwl_req_fw_callback+0x1a28/0x1ddc [iwlwifi]
[   13.552308]  request_firmware_work_func+0x50/0x9c
[   13.552320]  process_one_work+0x194/0x25c

That's not a driver problem, that's an ordering issue vs. the devres
muck. Let me go back to the drawing board. Sigh...

Thanks,

        tglx