[PATCH] PCI: qcom: Fix error handling in pm_runtime support

From: Bjorn Andersson
Date: Fri May 25 2018 - 15:09:43 EST


The driver does not cope with the fact that probe can fail in a number
of cases after enabling pm_runtime on the device, this results in
warnings about "Unbalanced pm_runtime_enable". Further more if probe
fails after invoking host_init the power-domain will be left referenced.

As it's not possible for the error handling in qcom_pcie_host_init() to
handle errors happening after returning from that function the
pm_runtime_get_sync() is moved to probe() as well.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---

I'm sorry for not spotting this last week when we discussed the previous patch.

drivers/pci/dwc/pcie-qcom.c | 65 ++++++++++++++++++++++++++-----------
1 file changed, 46 insertions(+), 19 deletions(-)

diff --git a/drivers/pci/dwc/pcie-qcom.c b/drivers/pci/dwc/pcie-qcom.c
index 3f35098b71b1..f2453196278f 100644
--- a/drivers/pci/dwc/pcie-qcom.c
+++ b/drivers/pci/dwc/pcie-qcom.c
@@ -1088,8 +1088,6 @@ static int qcom_pcie_host_init(struct pcie_port *pp)
struct qcom_pcie *pcie = to_qcom_pcie(pci);
int ret;

- pm_runtime_get_sync(pci->dev);
-
qcom_ep_reset_assert(pcie);

ret = pcie->ops->init(pcie);
@@ -1126,7 +1124,6 @@ static int qcom_pcie_host_init(struct pcie_port *pp)
phy_power_off(pcie->phy);
err_deinit:
pcie->ops->deinit(pcie);
- pm_runtime_put_sync(pci->dev);

return ret;
}
@@ -1207,7 +1204,6 @@ static int qcom_pcie_probe(struct platform_device *pdev)
struct qcom_pcie *pcie;
int ret;

-
pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
if (!pcie)
return -ENOMEM;
@@ -1217,6 +1213,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
return -ENOMEM;

pm_runtime_enable(dev);
+ pm_runtime_get_sync(dev);

pci->dev = dev;
pci->ops = &dw_pcie_ops;
@@ -1227,53 +1224,82 @@ static int qcom_pcie_probe(struct platform_device *pdev)
pcie->ops = of_device_get_match_data(dev);

pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_LOW);
- if (IS_ERR(pcie->reset))
- return PTR_ERR(pcie->reset);
+ if (IS_ERR(pcie->reset)) {
+ ret = PTR_ERR(pcie->reset);
+ goto err_pm_runtime_put;
+ }

res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "parf");
pcie->parf = devm_ioremap_resource(dev, res);
- if (IS_ERR(pcie->parf))
- return PTR_ERR(pcie->parf);
+ if (IS_ERR(pcie->parf)) {
+ ret = PTR_ERR(pcie->parf);
+ goto err_pm_runtime_put;
+ }

res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
pci->dbi_base = devm_pci_remap_cfg_resource(dev, res);
- if (IS_ERR(pci->dbi_base))
- return PTR_ERR(pci->dbi_base);
+ if (IS_ERR(pci->dbi_base)) {
+ ret = PTR_ERR(pci->dbi_base);
+ goto err_pm_runtime_put;
+ }

res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
pcie->elbi = devm_ioremap_resource(dev, res);
- if (IS_ERR(pcie->elbi))
- return PTR_ERR(pcie->elbi);
+ if (IS_ERR(pcie->elbi)) {
+ ret = PTR_ERR(pcie->elbi);
+ goto err_pm_runtime_put;
+ }

pcie->phy = devm_phy_optional_get(dev, "pciephy");
- if (IS_ERR(pcie->phy))
- return PTR_ERR(pcie->phy);
+ if (IS_ERR(pcie->phy)) {
+ ret = PTR_ERR(pcie->phy);
+ goto err_pm_runtime_put;
+ }

ret = pcie->ops->get_resources(pcie);
if (ret)
- return ret;
+ goto err_pm_runtime_put;

pp->root_bus_nr = -1;
pp->ops = &qcom_pcie_dw_ops;

if (IS_ENABLED(CONFIG_PCI_MSI)) {
pp->msi_irq = platform_get_irq_byname(pdev, "msi");
- if (pp->msi_irq < 0)
- return pp->msi_irq;
+ if (pp->msi_irq < 0) {
+ ret = pp->msi_irq;
+ goto err_pm_runtime_put;
+ }
}

ret = phy_init(pcie->phy);
if (ret)
- return ret;
+ goto err_pm_runtime_put;

platform_set_drvdata(pdev, pcie);

ret = dw_pcie_host_init(pp);
if (ret) {
dev_err(dev, "cannot initialize host\n");
- return ret;
+ goto err_pm_runtime_put;
}

+ return 0;
+
+err_pm_runtime_put:
+ pm_runtime_put(dev);
+ pm_runtime_disable(dev);
+
+ return ret;
+}
+
+static int qcom_pcie_remove(struct platform_device *pdev)
+{
+ struct qcom_pcie *pcie = platform_get_drvdata(pdev);
+ struct device *dev = pcie->pci->dev;
+
+ pm_runtime_put(dev);
+ pm_runtime_disable(dev);
+
return 0;
}

@@ -1289,6 +1315,7 @@ static const struct of_device_id qcom_pcie_match[] = {

static struct platform_driver qcom_pcie_driver = {
.probe = qcom_pcie_probe,
+ .remove = qcom_pcie_remove,
.driver = {
.name = "qcom-pcie",
.suppress_bind_attrs = true,
--
2.17.0