Linux PCI subsystem development
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From: Wei Fang <wei.fang@nxp.com>
To: devnull+manivannan.sadhasivam.linaro.org@kernel.org
Cc: bartosz.golaszewski@linaro.org, bhelgaas@google.com,
	brgl@bgdev.pl, conor+dt@kernel.org, devicetree@vger.kernel.org,
	krzk+dt@kernel.org, linux-kernel@vger.kernel.org,
	linux-pci@vger.kernel.org, manivannan.sadhasivam@linaro.org,
	robh@kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH v3 3/5] PCI/pwrctrl: Skip scanning for the device further if pwrctrl device is created
Date: Fri, 21 Mar 2025 10:59:40 +0800	[thread overview]
Message-ID: <20250321025940.2103854-1-wei.fang@nxp.com> (raw)
In-Reply-To: <20250116-pci-pwrctrl-slot-v3-3-827473c8fbf4@linaro.org>

@@ -2487,7 +2487,14 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
 	struct pci_dev *dev;
 	u32 l;
 
-	pci_pwrctrl_create_device(bus, devfn);
+	/*
+	 * Create pwrctrl device (if required) for the PCI device to handle the
+	 * power state. If the pwrctrl device is created, then skip scanning
+	 * further as the pwrctrl core will rescan the bus after powering on
+	 * the device.
+	 */
+	if (pci_pwrctrl_create_device(bus, devfn))
+		return NULL;

Hi Manivannan,

The current patch logic is that if the pcie device node is found to have
the "xxx-supply" property, the scan will be skipped, and then the pwrctrl
driver will rescan and enable the regulators. However, after merging this
patch, there is a problem on our platform. The .probe() of our device
driver will not be called. The reason is that CONFIG_PCI_PWRCTL_SLOT is
not enabled at all in our configuration file, and the compatible string
of the device is also not added to the pwrctrl driver. I think other
platforms should also have similar problems, which undoubtedly make these
platforms be unstable. This patch has been applied, and I am not familiar
with this. Can you fix this problem? I mean that those platforms that do
not use pwrctrl can avoid skipping the scan.

  parent reply	other threads:[~2025-03-21  2:58 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-16 14:09 [PATCH v3 0/5] PCI/pwrctrl: Rework pwrctrl driver integration and add driver for PCI slot Manivannan Sadhasivam via B4 Relay
2025-01-16 14:09 ` [PATCH v3 1/5] PCI/pwrctrl: Move creation of pwrctrl devices to pci_scan_device() Manivannan Sadhasivam via B4 Relay
2025-01-16 14:09 ` [PATCH v3 2/5] PCI/pwrctrl: Move pci_pwrctrl_unregister() to pci_destroy_dev() Manivannan Sadhasivam via B4 Relay
2025-04-13 21:08   ` Lukas Wunner
2025-01-16 14:09 ` [PATCH v3 3/5] PCI/pwrctrl: Skip scanning for the device further if pwrctrl device is created Manivannan Sadhasivam via B4 Relay
2025-02-20 23:24   ` Bjorn Helgaas
2025-02-21 17:38     ` Manivannan Sadhasivam
2025-02-20 23:35   ` Bjorn Helgaas
2025-02-21 17:40     ` Manivannan Sadhasivam
2025-03-21  2:59   ` Wei Fang [this message]
2025-03-21  4:42     ` Manivannan Sadhasivam
2025-03-21  7:04       ` Wei Fang
2025-03-22  3:23         ` Manivannan Sadhasivam
2025-03-22 11:39           ` Wei Fang
2025-03-24  8:15             ` Manivannan Sadhasivam
2025-03-27  6:02               ` Wei Fang
2025-04-02  8:14                 ` Manivannan Sadhasivam
2025-01-16 14:09 ` [PATCH v3 4/5] dt-bindings: vendor-prefixes: Document the 'pciclass' prefix Manivannan Sadhasivam via B4 Relay
2025-01-16 14:09 ` [PATCH v3 5/5] PCI/pwrctrl: Add pwrctrl driver for PCI Slots Manivannan Sadhasivam via B4 Relay
2025-02-20 14:24 ` [PATCH v3 0/5] PCI/pwrctrl: Rework pwrctrl driver integration and add driver for PCI slot Krzysztof Wilczyński

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