[PATCH] pinctrl: add some comments to the hog/late init code

From: Linus Walleij
Date: Fri Dec 30 2016 - 08:45:43 EST


It confused me a bit so it may confuse others. Make it crystal
clear what is going on here for any future readers.

Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/pinctrl/core.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index d02e8def9506..a9e3a75fb67d 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -1753,6 +1753,12 @@ static void pinctrl_late_init(struct work_struct *work)

pctldev = container_of(work, struct pinctrl_dev, late_init.work);

+ /*
+ * If the pin controller does NOT have hogs, this will report an
+ * error and we skip over this entire branch. This is why we can
+ * call this function directly when we do not have hogs on the
+ * device.
+ */
pctldev->p = create_pinctrl(pctldev->dev, pctldev);
if (!IS_ERR(pctldev->p)) {
kref_get(&pctldev->p->users);
@@ -1847,6 +1853,12 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
goto out_err;
}

+ /*
+ * If the device has hogs we want the probe() function of the driver
+ * to complete before we go in and hog them and add the pin controller
+ * to the list of controllers. If it has no hogs, we can just complete
+ * the registration immediately.
+ */
if (pinctrl_dt_has_hogs(pctldev))
schedule_delayed_work(&pctldev->late_init, 0);
else
--
2.9.3