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authorSaravana Kannan <saravanak@google.com>2020-07-01 12:42:57 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-07-10 15:20:38 +0200
commitcec72f3efc6272420c2c2c699607f03d09b93e41 (patch)
treee8645d83c161bcc856de5ecd6d231c4a9787e00d /drivers/base/dd.c
parent9ebcfadb0610322ac537dd7aa5d9cbc2b2894c68 (diff)
downloadlinux-cec72f3efc6272420c2c2c699607f03d09b93e41.tar.bz2
driver core: Don't do deferred probe in parallel with kernel_init thread
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-6Q@mail.gmail.com/ 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/20200701194259.3337652-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/dd.c')
-rw-r--r--drivers/base/dd.c5
1 files changed, 0 insertions, 5 deletions
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