pci_alloc_irq_vectors fails ENOSPC for XPS 13 9310

[Kalle Valo]

Kalle Valo <kvalo at codeaurora.org> writes:

> Thomas Gleixner <tglx at linutronix.de> writes:
>
>> On Wed, Nov 04 2020 at 14:04, Thomas Krause wrote:
>>> config) but CONFIG_INTEL_IOMMU_DEFAULT_ON needed to be set manually. I 
>>> hope this helps, if there is more I can do to debug it on my side I'm 
>>> happy to do so.
>>
>>> [ 0.050130] DMAR: [Firmware Bug]: Your BIOS is broken; DMAR
>>> reported at address 0!
>>>                BIOS vendor: Dell Inc.; Ver: 1.1.1; Product Version:
>>
>>> [    0.103693] DMAR: Host address width 39
>>> [    0.103693] DMAR: DRHD base: 0x000000fed90000 flags: 0x0
>>> [ 0.103697] DMAR: dmar0: reg_base_addr fed90000 ver 4:0 cap
>>> 1c0000c40660462 ecap 69e2ff0505e
>>> [    0.103698] DMAR: DRHD base: 0x000000fed84000 flags: 0x0
>>> [ 0.103701] DMAR: dmar1: reg_base_addr fed84000 ver 1:0 cap
>>> d2008c40660462 ecap f050da
>>> [    0.103702] DMAR: DRHD base: 0x000000fed86000 flags: 0x0
>>> [ 0.103706] DMAR: dmar2: reg_base_addr fed86000 ver 1:0 cap
>>> d2008c40660462 ecap f050da
>>> [    0.103707] DMAR: DRHD base: 0x00000000000000 flags: 0x1
>>> [    0.103707] DMAR: Parse DMAR table failure.
>>
>> which disables interrupt remapping and therefore the driver gets only
>> one MSI which makes it unhappy.
>>
>> Not that I'm surprised, it's Dell.... Can you check whether they have a
>> BIOS update for that box?
>
> I was told that on Dell XPS 15 (with a working QCA6390 setup) there's a
> separate "Virtualisation" setting in BIOS. See if you have that and try
> enabling it.

I was informed about another setting to test: try disabling "Enable
Secure Boot" in the BIOS. I don't know yet why it would help, but that's
what few people have recommended.

Please let me know how it goes.

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