2018-12-26 19:22:34

by Kangjie Lu

Subject: [PATCH v2] usb: chipidea: add a check for the availability of next child

of_get_next_available_child returns NULL when no child nodes are found.
The fix checks its return value instead of assuming a child is found.

Signed-off-by: Kangjie Lu <[email protected]>
---
drivers/usb/chipidea/ci_hdrc_msm.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/usb/chipidea/ci_hdrc_msm.c b/drivers/usb/chipidea/ci_hdrc_msm.c
index 880009987460..b7f7acef72d4 100644
--- a/drivers/usb/chipidea/ci_hdrc_msm.c
+++ b/drivers/usb/chipidea/ci_hdrc_msm.c
@@ -250,6 +250,10 @@ static int ci_hdrc_msm_probe(struct platform_device *pdev)
ulpi_node = of_get_child_by_name(pdev->dev.of_node, "ulpi");
if (ulpi_node) {
phy_node = of_get_next_available_child(ulpi_node, NULL);
+ if (!phy_node) {
+ dev_err(&pdev->dev, "no child nodes found\n");
+ return -ENODEV;
+ }
ci->hsic = of_device_is_compatible(phy_node, "qcom,usb-hsic-phy");
of_node_put(phy_node);
}
--
2.17.2 (Apple Git-113)

2018-12-27 14:34:38

by Peter Chen

Subject: RE: [PATCH v2] usb: chipidea: add a check for the availability of next child

> Signed-off-by: Kangjie Lu <[email protected]>
> ---
> drivers/usb/chipidea/ci_hdrc_msm.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/usb/chipidea/ci_hdrc_msm.c
> b/drivers/usb/chipidea/ci_hdrc_msm.c
> index 880009987460..b7f7acef72d4 100644
> --- a/drivers/usb/chipidea/ci_hdrc_msm.c
> +++ b/drivers/usb/chipidea/ci_hdrc_msm.c
> @@ -250,6 +250,10 @@ static int ci_hdrc_msm_probe(struct platform_device
> *pdev)
> ulpi_node = of_get_child_by_name(pdev->dev.of_node, "ulpi");
> if (ulpi_node) {
> phy_node = of_get_next_available_child(ulpi_node, NULL);
> + if (!phy_node) {
> + dev_err(&pdev->dev, "no child nodes found\n");
> + return -ENODEV;
> + }

There are still two issues for this patch:
- It can't return -ENODEV directly, instead, it needs to goto err_mux
- Before goto err_mux, it needs to call of_node_put(ulpi_node);

Besides, for kernel code style, you may leave one blank line after if () {} statement.

Peter

> ci->hsic = of_device_is_compatible(phy_node, "qcom,usb-hsic-phy");
> of_node_put(phy_node);
> }
> --
> 2.17.2 (Apple Git-113)