| Message ID | 1466090861-4538-1-git-send-email-jonathanh@nvidia.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Jun 16, 2016 at 5:27 PM, Jon Hunter <jonathanh@nvidia.com> wrote: > When pinctrl_get() is called for a device, it will return a valid handle > even if the device itself has no pinctrl state entries defined in > device-tree. This is caused by the function pinctrl_dt_to_map() which > will return success even if the first pinctrl state, 'pinctrl-0', is not > found in the device-tree node for a device. > > According to the pinctrl device-tree binding documentation, pinctrl > states must be numbered starting from 0 and so 'pinctrl-0' should always > be present if a device uses pinctrl and therefore, if 'pinctrl-0' is not > present it seems valid that we should not return a valid pinctrl handle. > > Fix this by returning an error code if the property 'pinctrl-0' is not > present for a device. > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Patch applied (after adding OF to the subject) It's a bit dangerous because it changes semantics but let's see if we survive it. > I was wondering if this meant we are creating pinctrl handles for > devices on boot that don't use pinctrl (when > calling pinctrl_bind_pins()). However, although devm_pinctrl_get() > does return successful for all devices, the subsequent call to > pinctrl_lookup_state() (to get the default state) will fail and so > we will destroy the pinctrl handle afterall. It's better like this, logically. I'm just worried that there may be code in the tree that depend on the bind always getting a handle. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c index fe04e748dfe4..54dad89fc9bf 100644 --- a/drivers/pinctrl/devicetree.c +++ b/drivers/pinctrl/devicetree.c @@ -195,8 +195,13 @@ int pinctrl_dt_to_map(struct pinctrl *p) propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state); prop = of_find_property(np, propname, &size); kfree(propname); - if (!prop) + if (!prop) { + if (state == 0) { + of_node_put(np); + return -ENODEV; + } break; + } list = prop->value; size /= sizeof(*list);
When pinctrl_get() is called for a device, it will return a valid handle even if the device itself has no pinctrl state entries defined in device-tree. This is caused by the function pinctrl_dt_to_map() which will return success even if the first pinctrl state, 'pinctrl-0', is not found in the device-tree node for a device. According to the pinctrl device-tree binding documentation, pinctrl states must be numbered starting from 0 and so 'pinctrl-0' should always be present if a device uses pinctrl and therefore, if 'pinctrl-0' is not present it seems valid that we should not return a valid pinctrl handle. Fix this by returning an error code if the property 'pinctrl-0' is not present for a device. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> --- Changes since V1: - Added of_node_put() I was wondering if this meant we are creating pinctrl handles for devices on boot that don't use pinctrl (when calling pinctrl_bind_pins()). However, although devm_pinctrl_get() does return successful for all devices, the subsequent call to pinctrl_lookup_state() (to get the default state) will fail and so we will destroy the pinctrl handle afterall. drivers/pinctrl/devicetree.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)