diff mbox series

[v2,4/6] PCI/pwrctrl: Skip scanning for the device further if pwrctrl device is created

Message ID 20241231-pci-pwrctrl-slot-v2-4-6a15088ba541@linaro.org (mailing list archive)
State New
Headers show
Series PCI/pwrctrl: Rework pwrctrl driver integration and add driver for PCI slot | expand

Commit Message

Manivannan Sadhasivam via B4 Relay Dec. 31, 2024, 9:43 a.m. UTC 
From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

The pwrctrl core will rescan the bus once the device is powered on. So
there is no need to continue scanning for the device further.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/probe.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

Comments

Bartosz Golaszewski Jan. 3, 2025, 8:37 p.m. UTC | #1 
On Tue, Dec 31, 2024 at 10:44 AM Manivannan Sadhasivam via B4 Relay
<devnull+manivannan.sadhasivam.linaro.org@kernel.org> wrote:
>
> From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
>
> The pwrctrl core will rescan the bus once the device is powered on. So
> there is no need to continue scanning for the device further.
>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
diff mbox series

Patch

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 91bdb2727c8e..6121f81f7c98 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2448,11 +2448,7 @@  bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
 }
 EXPORT_SYMBOL(pci_bus_read_dev_vendor_id);
 
-/*
- * Create pwrctrl device (if required) for the PCI device to handle the power
- * state.
- */
-static void pci_pwrctrl_create_device(struct pci_bus *bus, int devfn)
+static struct platform_device *pci_pwrctrl_create_device(struct pci_bus *bus, int devfn)
 {
 	struct pci_host_bridge *host = pci_find_host_bridge(bus);
 	struct platform_device *pdev;
@@ -2460,7 +2456,7 @@  static void pci_pwrctrl_create_device(struct pci_bus *bus, int devfn)
 
 	np = of_pci_find_child_device(dev_of_node(&bus->dev), devfn);
 	if (!np || of_find_device_by_node(np))
-		return;
+		return NULL;
 
 	/*
 	 * First check whether the pwrctrl device really needs to be created or
@@ -2469,13 +2465,17 @@  static void pci_pwrctrl_create_device(struct pci_bus *bus, int devfn)
 	 */
 	if (!of_pci_supply_present(np)) {
 		pr_debug("PCI/pwrctrl: Skipping OF node: %s\n", np->name);
-		return;
+		return NULL;
 	}
 
 	/* Now create the pwrctrl device */
 	pdev = of_platform_device_create(np, NULL, &host->dev);
-	if (!pdev)
-		pr_err("PCI/pwrctrl: Failed to create pwrctrl device for OF node: %s\n", np->name);
+	if (!pdev) {
+		pr_err("PCI/pwrctrl: Failed to create pwrctrl device for node: %s\n", np->name);
+		return NULL;
+	}
+
+	return pdev;
 }
 
 /*
@@ -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;
 
 	if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000))
 		return NULL;