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From: Lukas Wunner <lukas@wunner.de>
To: "Jozef Matejcik (Nokia)" <jozef.matejcik@nokia.com>
Cc: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>
Subject: Re: pci_probe called concurrently in machine with 2 identical PCI devices causing race condition
Date: Thu, 26 Jun 2025 14:08:31 +0200	[thread overview]
Message-ID: <aF04PxJ5WqIA7Je0@wunner.de> (raw)
In-Reply-To: <AS4PR07MB85085806C2BF5CC518D52808937AA@AS4PR07MB8508.eurprd07.prod.outlook.com>

On Thu, Jun 26, 2025 at 10:14:00AM +0000, Jozef Matejcik (Nokia) wrote:
> We have one specific problem related to Linux PCI subsystem.
> 
> We have a device with 2 identical NPUs, so 2 identical PCI devices
> sharing the same 3rd party driver. Our problem is that _pci_probe of
> this driver is called concurrently from 2 kernel threads. It happens
> more frequently when kernel debug logs are enabled in GRUB, appr.
> every 20th or 30th reboot of the device.

So what exactly is the "problem"?  Does something not work?
Do you get errors or warnings?

> So the fix is specifically related to devices with multiple VFs.
> But does this take into account the setup with 2 separate, but
> otherwise identical PCI devices? Is it possible this can occur
> in any machine with 2 identical PCI devices?

Not unless probing of one PF creates another PF.

Thanks,

Lukas

  reply	other threads:[~2025-06-26 12:08 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-26 10:14 pci_probe called concurrently in machine with 2 identical PCI devices causing race condition Jozef Matejcik (Nokia)
2025-06-26 12:08 ` Lukas Wunner [this message]
2025-06-26 12:20   ` Jozef Matejcik (Nokia)
2025-06-26 12:26     ` Lukas Wunner
2025-06-26 15:41       ` Keith Busch
2025-06-26 18:16         ` Jozef Matejcik (Nokia)
2025-06-26 22:37           ` Keith Busch
2025-07-04  8:03         ` Lukas Wunner

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