diff options
| author | Saravana Kannan <saravanak@google.com> | 2020-07-01 12:42:59 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-10 15:20:38 +0200 |
| commit | 2451e746478a6a6e981cfa66b62b791ca93b90c8 (patch) | |
| tree | b660ac8be26217ce7ce9664715d660991ff856da /drivers/base | |
| parent | ec7bd78498f29680f536451fbdf9464e851273ed (diff) | |
driver core: Avoid deferred probe due to fw_devlink_pause/resume()
With the earlier patch in this series, all devices that deferred probe
due to fw_devlink_pause() will have their probes delayed till the
deferred probe thread is kicked off during late_initcall. This will also
affect all their consumers.
This delayed probing in unnecessary. So this patch just keeps track of
the devices that had their probe deferred due to fw_devlink_pause() and
attempts to probe them once during fw_devlink_resume().
Fixes: 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200701194259.3337652-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/core.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index d1d2cdc3a8d8..05d414e9e8a4 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -50,6 +50,7 @@ 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); @@ -1244,6 +1245,12 @@ 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) @@ -1312,6 +1319,9 @@ 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!"); @@ -1323,8 +1333,19 @@ 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. */ |