From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Date: Sat, 9 May 2020 14:08:13 +0000 (+0200)
Subject: gpiolib: notify user-space about line status changes after flags are set
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9fefca775c8ddbbbcd97f2860218188b8641819d;p=linux.git

gpiolib: notify user-space about line status changes after flags are set

Currently we emit the REQUESTED line state event after the line is
requested but before the flags are configured. This is obviously wrong
as we want to pass the updated lineinfo to user-space together with the
event.

Since the flags can be configured in different ways depending on how the
line is being requested - we need to call the notifier chain in different
places separately.

Fixes: 51c1064e82e7 ("gpiolib: add new ioctl() for monitoring changes in line info")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index bf9732ab7f91b..66cb3ca401842 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -729,6 +729,10 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 			if (ret)
 				goto out_free_descs;
 		}
+
+		atomic_notifier_call_chain(&desc->gdev->notifier,
+					   GPIOLINE_CHANGED_REQUESTED, desc);
+
 		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
 			offset);
 	}
@@ -1083,6 +1087,9 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
 	if (ret)
 		goto out_free_desc;
 
+	atomic_notifier_call_chain(&desc->gdev->notifier,
+				   GPIOLINE_CHANGED_REQUESTED, desc);
+
 	le->irq = gpiod_to_irq(desc);
 	if (le->irq <= 0) {
 		ret = -ENODEV;
@@ -2998,8 +3005,6 @@ static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
 	}
 done:
 	spin_unlock_irqrestore(&gpio_lock, flags);
-	atomic_notifier_call_chain(&desc->gdev->notifier,
-				   GPIOLINE_CHANGED_REQUESTED, desc);
 	return ret;
 }
 
@@ -4961,6 +4966,9 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
 		return ERR_PTR(ret);
 	}
 
+	atomic_notifier_call_chain(&desc->gdev->notifier,
+				   GPIOLINE_CHANGED_REQUESTED, desc);
+
 	return desc;
 }
 EXPORT_SYMBOL_GPL(gpiod_get_index);
@@ -5026,6 +5034,9 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 		return ERR_PTR(ret);
 	}
 
+	atomic_notifier_call_chain(&desc->gdev->notifier,
+				   GPIOLINE_CHANGED_REQUESTED, desc);
+
 	return desc;
 }
 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);