Fix child-node lookups during probe, which ended up searching the whole device tree depth-first starting at the parents rather than just matching on their children.

To make things worse, some parent nodes could end up being being prematurely freed (by tegra_xusb_pad_register()) as of_find_node_by_name() drops a reference to its first argument.

Fixes: 53d2a715c240 ("phy: Add Tegra XUSB pad controller support") Cc: stable stable@vger.kernel.org # 4.7 Cc: Thierry Reding treding@nvidia.com Signed-off-by: Johan Hovold johan@kernel.org --- drivers/phy/tegra/xusb.c | 58 ++++++++++++++++++++++++------------------------ 1 file changed, 29 insertions(+), 29 deletions(-)

diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c index 4307bf0013e1..63e916d4d069 100644 --- a/drivers/phy/tegra/xusb.c +++ b/drivers/phy/tegra/xusb.c @@ -75,14 +75,14 @@ MODULE_DEVICE_TABLE(of, tegra_xusb_padctl_of_match); static struct device_node * tegra_xusb_find_pad_node(struct tegra_xusb_padctl *padctl, const char *name) { - /* - * of_find_node_by_name() drops a reference, so make sure to grab one. - */ - struct device_node *np = of_node_get(padctl->dev->of_node); + struct device_node *pads, *np; + + pads = of_get_child_by_name(padctl->dev->of_node, "pads"); + if (!pads) + return NULL;

- np = of_find_node_by_name(np, "pads"); - if (np) - np = of_find_node_by_name(np, name); + np = of_get_child_by_name(pads, name); + of_node_put(pads);

return np; } @@ -90,16 +90,16 @@ tegra_xusb_find_pad_node(struct tegra_xusb_padctl *padctl, const char *name) static struct device_node * tegra_xusb_pad_find_phy_node(struct tegra_xusb_pad *pad, unsigned int index) { - /* - * of_find_node_by_name() drops a reference, so make sure to grab one. - */ - struct device_node *np = of_node_get(pad->dev.of_node); + struct device_node *np, *lanes;

- np = of_find_node_by_name(np, "lanes"); - if (!np) + lanes = of_get_child_by_name(pad->dev.of_node, "lanes"); + if (!lanes) return NULL;

- return of_find_node_by_name(np, pad->soc->lanes[index].name); + np = of_get_child_by_name(lanes, pad->soc->lanes[index].name); + of_node_put(lanes); + + return np; }

static int @@ -195,7 +195,7 @@ int tegra_xusb_pad_register(struct tegra_xusb_pad *pad, unsigned int i; int err;

- children = of_find_node_by_name(pad->dev.of_node, "lanes"); + children = of_get_child_by_name(pad->dev.of_node, "lanes"); if (!children) return -ENODEV;

@@ -444,21 +444,21 @@ static struct device_node * tegra_xusb_find_port_node(struct tegra_xusb_padctl *padctl, const char *type, unsigned int index) { - /* - * of_find_node_by_name() drops a reference, so make sure to grab one. - */ - struct device_node *np = of_node_get(padctl->dev->of_node); + struct device_node *ports, *np; + char *name;

- np = of_find_node_by_name(np, "ports"); - if (np) { - char *name; + ports = of_get_child_by_name(padctl->dev->of_node, "ports"); + if (!ports) + return NULL;

- name = kasprintf(GFP_KERNEL, "%s-%u", type, index); - if (!name) - return ERR_PTR(-ENOMEM); - np = of_find_node_by_name(np, name); - kfree(name); + name = kasprintf(GFP_KERNEL, "%s-%u", type, index); + if (!name) { + of_node_put(ports); + return ERR_PTR(-ENOMEM); } + np = of_get_child_by_name(ports, name); + kfree(name); + of_node_put(ports);

return np; } @@ -847,7 +847,7 @@ static void tegra_xusb_remove_ports(struct tegra_xusb_padctl *padctl)

static int tegra_xusb_padctl_probe(struct platform_device *pdev) { - struct device_node *np = of_node_get(pdev->dev.of_node); + struct device_node *np = pdev->dev.of_node; const struct tegra_xusb_padctl_soc *soc; struct tegra_xusb_padctl *padctl; const struct of_device_id *match; @@ -855,7 +855,7 @@ static int tegra_xusb_padctl_probe(struct platform_device *pdev) int err;

/* for backwards compatibility with old device trees */ - np = of_find_node_by_name(np, "pads"); + np = of_get_child_by_name(np, "pads"); if (!np) { dev_warn(&pdev->dev, "deprecated DT, using legacy driver\n"); return tegra_xusb_padctl_legacy_probe(pdev);