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From: Lukas Wunner <lukas@wunner.de>
To: Mario Limonciello <mario.limonciello@amd.com>
Cc: bhelgaas@google.com,
	"Mario Limonciello (AMD)" <superm1@kernel.org>,
	linux-pci@vger.kernel.org
Subject: Re: [PATCH] PCI: pciehp: Disable link and turn off slot power while removing
Date: Thu, 7 May 2026 06:26:56 +0200	[thread overview]
Message-ID: <afwUkP1P-HNfMulV@wunner.de> (raw)
In-Reply-To: <9cfc10f8-de54-4af9-8436-35ebeef4faf6@amd.com>

On Wed, May 06, 2026 at 02:16:10PM -0500, Mario Limonciello wrote:
> On 5/6/26 12:55, Lukas Wunner wrote:
> > Moreover there are products where Presence Detect is hardwired to zero,
> > see commit 80696f991424 ("PCI: pciehp: Tolerate Presence Detect hardwired
> > to zero").  So we have to rely on a link change to detect that a new device
> > has been plugged in after slot poweroff.  That won't work if the link is
> > disabled.
> 
> How would you feel about turning off link detect somewhere specific to the
> shutdown path?

I *think* shutdown is performed bottom-up in the hierarchy and so
this might work.  But it's not great to introduce such a change
for everyone just because a single product needs it.  It would
be better to root-cause the issue.  Maybe the vendor is able to
provide a BIOS update which resolves it?

Thanks,

Lukas

  reply	other threads:[~2026-05-07  4:26 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-06 16:43 [PATCH] PCI: pciehp: Disable link and turn off slot power while removing Mario Limonciello
2026-05-06 17:55 ` Lukas Wunner
2026-05-06 19:16   ` Mario Limonciello
2026-05-07  4:26     ` Lukas Wunner [this message]
2026-05-07  5:03       ` Mario Limonciello
2026-05-06 20:58 ` sashiko-bot

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