[PATCH v2 01/17] Revert "driver core: Avoid deferred probe due to fw_devlink_pause/resume()"

From: Saravana Kannan
Date: Fri Nov 20 2020 - 21:02:58 EST


This reverts commit 2451e746478a6a6e981cfa66b62b791ca93b90c8.

fw_devlink_pause/resume() was an incomplete attempt at boot time
optimization. That's going to get replaced by a much better optimization
at the end of the series. Since fw_devlink_pause/resume() is going away,
changes made for that can also go away.

Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
---
drivers/base/core.c | 21 ---------------------
include/linux/device.h | 3 +--
2 files changed, 1 insertion(+), 23 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index d661ada1518f..b202fe54f46a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -51,7 +51,6 @@ static DEFINE_MUTEX(wfs_lock);
static LIST_HEAD(deferred_sync);
static unsigned int defer_sync_state_count = 1;
static unsigned int defer_fw_devlink_count;
-static LIST_HEAD(deferred_fw_devlink);
static DEFINE_MUTEX(defer_fw_devlink_lock);
static bool fw_devlink_is_permissive(void);

@@ -1470,12 +1469,6 @@ static void fw_devlink_link_device(struct device *dev)
fw_ret = -EAGAIN;
} else {
fw_ret = -ENODEV;
- /*
- * defer_hook is not used to add device to deferred_sync list
- * until device is bound. Since deferred fw devlink also blocks
- * probing, same list hook can be used for deferred_fw_devlink.
- */
- list_add_tail(&dev->links.defer_hook, &deferred_fw_devlink);
}

if (fw_ret == -ENODEV)
@@ -1544,9 +1537,6 @@ void fw_devlink_pause(void)
*/
void fw_devlink_resume(void)
{
- struct device *dev, *tmp;
- LIST_HEAD(probe_list);
-
mutex_lock(&defer_fw_devlink_lock);
if (!defer_fw_devlink_count) {
WARN(true, "Unmatched fw_devlink pause/resume!");
@@ -1558,19 +1548,8 @@ void fw_devlink_resume(void)
goto out;

device_link_add_missing_supplier_links();
- list_splice_tail_init(&deferred_fw_devlink, &probe_list);
out:
mutex_unlock(&defer_fw_devlink_lock);
-
- /*
- * bus_probe_device() can cause new devices to get added and they'll
- * try to grab defer_fw_devlink_lock. So, this needs to be done outside
- * the defer_fw_devlink_lock.
- */
- list_for_each_entry_safe(dev, tmp, &probe_list, links.defer_hook) {
- list_del_init(&dev->links.defer_hook);
- bus_probe_device(dev);
- }
}
/* Device links support end. */

diff --git a/include/linux/device.h b/include/linux/device.h
index 5ed101be7b2e..da00f8e449bb 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -352,8 +352,7 @@ enum dl_dev_state {
* @suppliers: List of links to supplier devices.
* @consumers: List of links to consumer devices.
* @needs_suppliers: Hook to global list of devices waiting for suppliers.
- * @defer_hook: Hook to global list of devices that have deferred sync_state or
- * deferred fw_devlink.
+ * @defer_hook: Hook to global list of devices that have deferred sync_state.
* @need_for_probe: If needs_suppliers is on a list, this indicates if the
* suppliers are needed for probe or not.
* @status: Driver status information.
--
2.29.2.454.gaff20da3a2-goog