From: Lukas Wunner <lukas@wunner.de>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>, Len Brown <lenb@kernel.org>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-acpi@vger.kernel.org, mika.westerberg@linux.intel.com,
Hsin-Yi Wang <hsinyi@chromium.org>
Subject: Re: [PATCH v5 1/4] PCI/portdrv: Make use of pci_dev::bridge_d3 for checking the D3 possibility
Date: Tue, 6 Aug 2024 08:46:48 +0200 [thread overview]
Message-ID: <ZrHG2KnGp9N00mV_@wunner.de> (raw)
In-Reply-To: <20240805132442.GA7274@thinkpad>
On Mon, Aug 05, 2024 at 06:54:42PM +0530, Manivannan Sadhasivam wrote:
> So what is wrong in using pci_dev::bridge_d3?
The bridge_d3 flag may change at runtime, e.g. when writing to the
d3cold_allowed attribute in sysfs.
If e.g. bridge_d3 is set when pcie_portdrv_probe() runs but no longer
set when pcie_portdrv_remove() runs, there would be a runtime PM ref
imbalance. (Ref would be dropped on probe, but not reacquired on remove.)
> Again, pci_bridge_d3_possible() is not making use of values that could change
> dynamically.
Which is precisely the reason why it (and not the bridge_d3 flag) is
used by pcie_portdrv_{probe,remove,shutdown}().
Thanks,
Lukas
next prev parent reply other threads:[~2024-08-06 6:46 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-02 5:54 [PATCH v5 0/4] PCI: Allow D3Hot for PCI bridges in Devicetree based platforms Manivannan Sadhasivam via B4 Relay
2024-08-02 5:55 ` [PATCH v5 1/4] PCI/portdrv: Make use of pci_dev::bridge_d3 for checking the D3 possibility Manivannan Sadhasivam via B4 Relay
2024-08-02 9:49 ` Lukas Wunner
2024-08-02 11:19 ` Rafael J. Wysocki
2024-08-02 20:07 ` Lukas Wunner
2024-08-05 13:24 ` Manivannan Sadhasivam
2024-08-06 6:46 ` Lukas Wunner [this message]
2024-08-06 11:48 ` Manivannan Sadhasivam
2024-08-02 5:55 ` [PATCH v5 2/4] PCI: Rename pci_bridge_d3_possible() to pci_bridge_d3_allowed() Manivannan Sadhasivam via B4 Relay
2024-08-03 11:03 ` kernel test robot
2024-08-05 13:26 ` Manivannan Sadhasivam
2024-08-02 5:55 ` [PATCH v5 3/4] PCI: Decouple D3Hot and D3Cold handling for bridges Manivannan Sadhasivam via B4 Relay
2024-08-19 12:44 ` Oliver Neukum
2024-08-20 6:00 ` Manivannan Sadhasivam
2024-08-20 23:45 ` Bjorn Helgaas
2024-08-29 6:10 ` Manivannan Sadhasivam
2024-08-21 1:45 ` Bjorn Helgaas
2024-08-28 15:52 ` Manivannan Sadhasivam
2024-08-28 21:07 ` Bjorn Helgaas
2024-08-29 5:22 ` Manivannan Sadhasivam
2024-11-21 18:54 ` Brian Norris
2024-08-02 5:55 ` [PATCH v5 4/4] PCI: Allow PCI bridges to go to D3Hot on all Devicetree based platforms Manivannan Sadhasivam via B4 Relay
2024-08-02 10:13 ` Lukas Wunner
2024-08-05 13:35 ` Manivannan Sadhasivam
2024-08-06 6:53 ` Lukas Wunner
2024-08-06 12:41 ` Manivannan Sadhasivam
2024-08-06 13:02 ` Lukas Wunner
2024-08-06 14:39 ` Manivannan Sadhasivam
2024-08-06 20:20 ` Lukas Wunner
2024-08-19 15:34 ` Manivannan Sadhasivam
2024-08-06 20:58 ` Hsin-Yi Wang
2024-11-21 18:53 ` Brian Norris
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