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From: sashiko-bot@kernel.org
To: "Krishna Chaitanya Chundru" <krishna.chundru@oss.qualcomm.com>
Cc: linux-pci@vger.kernel.org
Subject: Re: [PATCH v6 2/3] PCI: dwc: Force L2 link entry on shutdown/reboot without D3cold check
Date: Wed, 09 Sep 2026 12:34:30 +0000	[thread overview]
Message-ID: <20260909123430.7557B1F00A3A@smtp.kernel.org> (raw)
In-Reply-To: <20260909-shutdown-v6-2-62b7bd123236@oss.qualcomm.com>

> dw_pcie_suspend_noirq() normally calls pci_host_common_d3cold_possible()
> to check whether every downstream endpoint can be put into D3cold before
> bothering to move the link to L2. If no endpoint supports it, the
> function returns early and leaves the link up.
> 
> Querying D3cold support during shutdown is actively harmful, not just
> slow: pci_host_common_d3cold_possible() requires every active endpoint
> to already be in PCI_D3hot, and returns false otherwise. If any endpoint
> is still in D0 -- which is common, since endpoint drivers aren't
> guaranteed to have suspended by the time the host's shutdown path runs
> the check fails and dw_pcie_suspend_noirq() returns early without ever
> moving the link to L2, leaving it up right up to the point where the
> system cuts power/clocks to the controller.
> 
> Add a force parameter to dw_pcie_suspend_noirq() that callers set
> explicitly to force this behavior, still call
> pci_host_common_d3cold_possible() unconditionally, since it's also how
> pme_capable gets set, but ignore its return value and force L2 entry
> regardless when force is set.
> 
> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260909-shutdown-v6-0-62b7bd123236@oss.qualcomm.com?part=2


  reply	other threads:[~2026-09-09 12:34 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-09 12:24 [PATCH v6 0/3] PCI: qcom: Implement shutdown() to avoid SMMU/NoC errors on reboot Krishna Chaitanya Chundru
2026-09-09 12:24 ` [PATCH v6 1/3] PCI: host-common: Fix early bus-walk exit in d3cold_possible() Krishna Chaitanya Chundru
2026-09-09 12:29   ` sashiko-bot
2026-09-09 12:24 ` [PATCH v6 2/3] PCI: dwc: Force L2 link entry on shutdown/reboot without D3cold check Krishna Chaitanya Chundru
2026-09-09 12:34   ` sashiko-bot [this message]
2026-09-09 12:24 ` [PATCH v6 3/3] PCI: qcom: Implement shutdown() callback Krishna Chaitanya Chundru
2026-09-09 12:34   ` sashiko-bot
2026-09-09 12:36   ` Konrad Dybcio
2026-09-09 12:40     ` Krishna Chaitanya Chundru
2026-09-09 13:18       ` Konrad Dybcio
2026-09-10  3:26         ` Krishna Chaitanya Chundru
2026-09-11  6:00           ` Manivannan Sadhasivam
2026-09-09 12:38 ` [PATCH v6 0/3] PCI: qcom: Implement shutdown() to avoid SMMU/NoC errors on reboot Konrad Dybcio
2026-09-09 12:42   ` Krishna Chaitanya Chundru

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