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Date: Sat, 9 Aug 2025 07:52:30 +0900
From: Ammar Faizi <ammarfaizi2@gnuweeb.org>
To: Nam Cao <namcao@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>, Lukas Wunner <lukas@wunner.de>,
	Bjorn Helgaas <helgaas@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Linux PCI Mailing List <linux-pci@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
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	Armando Budianto <sprite@gnuweeb.org>,
	Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>,
	gwml@vger.gnuweeb.org
Subject: Re: [GIT PULL v2] PCI changes for v6.17
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+ Adding tglx as he's involved in reviewing that commit.

Context: https://lore.kernel.org/linux-pci/aJXYhfc%2F6DfcqfqF@linux.gnuweeb.org/

On Fri, Aug 08, 2025 at 08:07:03PM +0200, Nam Cao wrote:
> There is no point in bisecting before that commit, because the WARN_ON()
> is added by that commit, so you wouldn't see anything before that.

I didn't notice that. Good you pointed that out earlier.

> The WARN_ONCE() tells us that some devices down the PCI tree are
> allocating MSI, but VMD supports MSI-X only.
> 
> From the backtrace:
>    msi_create_device_irq_domain+0x1eb/0x290
>    __pci_enable_msi_range+0x106/0x300
>    pci_alloc_irq_vectors_affinity+0xc5/0x110
>    pcie_portdrv_probe+0x24e/0x610
> 
> It seems MSI-X are allocated first, but fail for some reason. Then
> fallback to MSI, which triggers the WARN_ON().
> 
> So we need to figure out why MSI-X allocation fail.
> 
> I may need to ask you to insert a bunch of printk() to help me pinpoint
> the problem. But let me stare at it first..

I can do that. Send me a git diff. I'll test it and back with the dmesg
output.

-- 
Ammar Faizi