[RFC PATCH] platform/x86: Move delayed work on system_dfl_wq

[Marco Crivellari <marco.crivellari@suse.com>]

Currently the code enqueue work items using {queue|mod}_delayed_work(),
using system_wq, which will be deprecated soon and replaced by
system_percpu_wq.

   commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")

The function(s) mentioned earlier, end up calling __queue_delayed_work(),
which set a global timer that could fire anywhere, enqueuing the work
where the timer fired.

Unbound works could benefit from scheduler task placement, to optimize
performance and power consumption.

Since the workqueue work doesn't rely on per-cpu variables, there is no
obvious reason that justify the use of a per-cpu workqueue. So change
system_wq with system_dfl_wq so that the work may benefit from
scheduler task placement.

Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
---
 drivers/platform/x86/hp/hp-wmi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
index 24c151289dd3..b7c12f943770 100644
--- a/drivers/platform/x86/hp/hp-wmi.c
+++ b/drivers/platform/x86/hp/hp-wmi.c
@@ -2388,7 +2388,7 @@ static int hp_wmi_apply_fan_settings(struct hp_wmi_hwmon_priv *priv)
 		ret = hp_wmi_fan_speed_max_set(1);
 		if (ret < 0)
 			return ret;
-		mod_delayed_work(system_wq, &priv->keep_alive_dwork,
+		mod_delayed_work(system_dfl_wq, &priv->keep_alive_dwork,
 				 secs_to_jiffies(KEEP_ALIVE_DELAY_SECS));
 		return 0;
 	case PWM_MODE_MANUAL:
@@ -2397,7 +2397,7 @@ static int hp_wmi_apply_fan_settings(struct hp_wmi_hwmon_priv *priv)
 		ret = hp_wmi_fan_speed_set(priv, pwm_to_rpm(priv->pwm, priv));
 		if (ret < 0)
 			return ret;
-		mod_delayed_work(system_wq, &priv->keep_alive_dwork,
+		mod_delayed_work(system_dfl_wq, &priv->keep_alive_dwork,
 				 secs_to_jiffies(KEEP_ALIVE_DELAY_SECS));
 		return 0;
 	case PWM_MODE_AUTO:
-- 
2.54.0