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PCI/pwrctrl: Power off child devices on power-on failure

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pci_pwrctrl_power_on_device() recursively powers on the child nodes of a
device before powering on the device itself. If powering on a child fails
(e.g. returning -EPROBE_DEFER), the function returned immediately, leaving
the sibling children that were already powered on in the same loop
iteration enabled.

Since probe deferral is a standard boot path, this leads to unbounded
regulator and clock enable increments across retries. The error path in
pci_pwrctrl_power_on_devices() only powers off the top-level children
processed before the failing one and explicitly stops at it, so it can
never clean up the siblings leaked deeper in the failed subtree.

Power off the sibling children that were successfully powered on before a
child fails, and power off all children if the device's own power_on()
fails after its children were already enabled. Switch to a manual child
iterator so the failing node can be tracked and its reference released in
the error path.

Fixes: b35cf3b6aa ("PCI/pwrctrl: Add APIs to power on/off pwrctrl devices")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Link: https://patch.msgid.link/20260909-pwrtctl-power-on-rallback-v1-1-412ef996ba27@oss.qualcomm.com
This commit is contained in:
Lorenzo Bianconi 2026-09-09 17:28:29 +02:00 committed by Bjorn Helgaas
parent 7bf2ebcb7c
commit b6087ff2b7
1 changed files with 17 additions and 2 deletions
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19
drivers/pci/pwrctrl/core.c
View File

@ -252,14 +252,16 @@ static int __pci_pwrctrl_power_on_device(struct device *dev)
static int pci_pwrctrl_power_on_device(struct device_node *np)
{
struct platform_device *pdev;
struct device_node *child;
int ret = 0;
for_each_available_child_of_node_scoped(np, child) {
for_each_available_child_of_node(np, child) {
ret = pci_pwrctrl_power_on_device(child);
if (ret)
return ret;
goto err_power_off;
}
child = NULL;
if (!pci_pwrctrl_is_required(np))
return 0;
@ -279,6 +281,19 @@ static int pci_pwrctrl_power_on_device(struct device_node *np)
platform_device_put(pdev);
if (ret)
goto err_power_off;
return 0;
err_power_off:
for_each_available_child_of_node_scoped(np, tmp) {
if (tmp == child)
break;
pci_pwrctrl_power_off_device(tmp);
}
of_node_put(child);
return ret;
}