diff mbox series

[v1,14/18] driver core: Use device's fwnode to check if it is waiting for suppliers

Message ID 20201104232356.4038506-15-saravanak@google.com
State Superseded
Headers show
Series [v1,01/18] Revert "driver core: Avoid deferred probe due to fw_devlink_pause/resume()" | expand

Commit Message

Saravana Kannan Nov. 4, 2020, 11:23 p.m. UTC
To check if a device is still waiting for its supplier devices to be
added, we used to check if the devices is in a global
waiting_for_suppliers list. Since the global list will be deleted in
subsequent patches, this patch stops using this check.

Instead, this patch uses a more device specific check. It checks if the
device's fwnode has any fwnode links that haven't been converted to
device links yet.

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/base/core.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

Comments

Rafael J. Wysocki Nov. 16, 2020, 4:34 p.m. UTC | #1
On Thu, Nov 5, 2020 at 12:24 AM Saravana Kannan <saravanak@google.com> wrote:
>
> To check if a device is still waiting for its supplier devices to be
> added, we used to check if the devices is in a global
> waiting_for_suppliers list. Since the global list will be deleted in
> subsequent patches, this patch stops using this check.

My kind of educated guess is that you want to drop
waiting_for_suppliers and that's why you want to use supplier links
here.

>
> Instead, this patch uses a more device specific check. It checks if the
> device's fwnode has any fwnode links that haven't been converted to
> device links yet.
>
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
>  drivers/base/core.c | 18 ++++++++----------
>  1 file changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 4ae5f2885ac5..d51dd564add1 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -51,6 +51,7 @@ static DEFINE_MUTEX(wfs_lock);
>  static LIST_HEAD(deferred_sync);
>  static unsigned int defer_sync_state_count = 1;
>  static DEFINE_MUTEX(fwnode_link_lock);
> +static bool fw_devlink_is_permissive(void);
>
>  /**
>   * fwnode_link_add - Create a link between two fwnode_handles.
> @@ -994,13 +995,13 @@ int device_links_check_suppliers(struct device *dev)
>          * Device waiting for supplier to become available is not allowed to
>          * probe.
>          */
> -       mutex_lock(&wfs_lock);
> -       if (!list_empty(&dev->links.needs_suppliers) &&
> -           dev->links.need_for_probe) {
> -               mutex_unlock(&wfs_lock);
> +       mutex_lock(&fwnode_link_lock);
> +       if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) &&
> +           !fw_devlink_is_permissive()) {
> +               mutex_unlock(&fwnode_link_lock);
>                 return -EPROBE_DEFER;
>         }
> -       mutex_unlock(&wfs_lock);
> +       mutex_unlock(&fwnode_link_lock);
>
>         device_links_write_lock();
>
> @@ -1166,10 +1167,7 @@ static ssize_t waiting_for_supplier_show(struct device *dev,
>         bool val;
>
>         device_lock(dev);
> -       mutex_lock(&wfs_lock);
> -       val = !list_empty(&dev->links.needs_suppliers)
> -             && dev->links.need_for_probe;
> -       mutex_unlock(&wfs_lock);

Why isn't the lock needed any more?

Or maybe it wasn't needed previously too?

> +       val = !list_empty(&dev->fwnode->suppliers);
>         device_unlock(dev);
>         return sysfs_emit(buf, "%u\n", val);
>  }
> @@ -2226,7 +2224,7 @@ static int device_add_attrs(struct device *dev)
>                         goto err_remove_dev_groups;
>         }
>
> -       if (fw_devlink_flags && !fw_devlink_is_permissive()) {
> +       if (fw_devlink_flags && !fw_devlink_is_permissive() && dev->fwnode) {

And why is this change needed?

>                 error = device_create_file(dev, &dev_attr_waiting_for_supplier);
>                 if (error)
>                         goto err_remove_dev_online;
> --
> 2.29.1.341.ge80a0c044ae-goog
>
diff mbox series

Patch

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 4ae5f2885ac5..d51dd564add1 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -51,6 +51,7 @@  static DEFINE_MUTEX(wfs_lock);
 static LIST_HEAD(deferred_sync);
 static unsigned int defer_sync_state_count = 1;
 static DEFINE_MUTEX(fwnode_link_lock);
+static bool fw_devlink_is_permissive(void);
 
 /**
  * fwnode_link_add - Create a link between two fwnode_handles.
@@ -994,13 +995,13 @@  int device_links_check_suppliers(struct device *dev)
 	 * Device waiting for supplier to become available is not allowed to
 	 * probe.
 	 */
-	mutex_lock(&wfs_lock);
-	if (!list_empty(&dev->links.needs_suppliers) &&
-	    dev->links.need_for_probe) {
-		mutex_unlock(&wfs_lock);
+	mutex_lock(&fwnode_link_lock);
+	if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) &&
+	    !fw_devlink_is_permissive()) {
+		mutex_unlock(&fwnode_link_lock);
 		return -EPROBE_DEFER;
 	}
-	mutex_unlock(&wfs_lock);
+	mutex_unlock(&fwnode_link_lock);
 
 	device_links_write_lock();
 
@@ -1166,10 +1167,7 @@  static ssize_t waiting_for_supplier_show(struct device *dev,
 	bool val;
 
 	device_lock(dev);
-	mutex_lock(&wfs_lock);
-	val = !list_empty(&dev->links.needs_suppliers)
-	      && dev->links.need_for_probe;
-	mutex_unlock(&wfs_lock);
+	val = !list_empty(&dev->fwnode->suppliers);
 	device_unlock(dev);
 	return sysfs_emit(buf, "%u\n", val);
 }
@@ -2226,7 +2224,7 @@  static int device_add_attrs(struct device *dev)
 			goto err_remove_dev_groups;
 	}
 
-	if (fw_devlink_flags && !fw_devlink_is_permissive()) {
+	if (fw_devlink_flags && !fw_devlink_is_permissive() && dev->fwnode) {
 		error = device_create_file(dev, &dev_attr_waiting_for_supplier);
 		if (error)
 			goto err_remove_dev_online;