The current deferred probe implementation can mess up suspend/resume
ordering if deferred probe thread is kicked off in parallel with the
main initcall thread (kernel_init thread) [1].
For example:
Say device-B is a consumer of device-A.
Initcall thread Deferred probe thread
=============== =====================
1. device-A is added.
2. device-B is added.
3. dpm_list is now [device-A, device-B].
4. driver-A defers probe of device-A.
5. device-A is moved to
end of dpm_list
6. dpm_list is now
[device-B, device-A]
7. driver-B is registereed and probes device-B.
8. dpm_list stays as [device-B, device-A].
The reverse order of dpm_list is used for suspend. So in this case
device-A would incorrectly get suspended before device-B.
Commit 716a7a259690 ("driver core: fw_devlink: Add support for batching
fwnode parsing") kicked off the deferred probe thread early during boot
to run in parallel with the initcall thread and caused suspend/resume
regressions. This patch removes the parallel run of the deferred probe
thread to avoid the suspend/resume regressions.
[1] -
https://lore.kernel.org/lkml/cagetcx8w96kaw-d_sitx4qhb_-7ddk0miyrdqehe6e0_8qx...@mail.gmail.com/
Fixes: 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode
parsing")
Signed-off-by: Saravana Kannan <[email protected]>
---
drivers/base/base.h | 1 -
drivers/base/core.c | 1 -
drivers/base/dd.c | 5 -----
3 files changed, 7 deletions(-)
diff --git a/drivers/base/base.h b/drivers/base/base.h
index 95c22c0f9036..40fb069a8a7e 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -153,7 +153,6 @@ extern char *make_class_name(const char *name, struct
kobject *kobj);
extern int devres_release_all(struct device *dev);
extern void device_block_probing(void);
extern void device_unblock_probing(void);
-extern void driver_deferred_probe_force_trigger(void);
/* /sys/devices directory */
extern struct kset *devices_kset;
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 67d39a90b45c..35cc9896eb9e 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1323,7 +1323,6 @@ void fw_devlink_resume(void)
goto out;
device_link_add_missing_supplier_links();
- driver_deferred_probe_force_trigger();
out:
mutex_unlock(&defer_fw_devlink_lock);
}
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 9a1d940342ac..48ca81cb8ebc 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -164,11 +164,6 @@ static void driver_deferred_probe_trigger(void)
if (!driver_deferred_probe_enable)
return;
- driver_deferred_probe_force_trigger();
-}
-
-void driver_deferred_probe_force_trigger(void)
-{
/*
* A successful probe means that all the devices in the pending list
* should be triggered to be reprobed. Move all the deferred devices
--
2.27.0.212.ge8ba1cc988-goog
