[PATCH AUTOSEL 5.15 07/37] PM / devfreq: rk3399_dmc: Disable edev on remove()

[PATCH AUTOSEL 5.15 07/37] PM / devfreq: rk3399_dmc: Disable edev on remove()

[Sasha Levin]

From: Brian Norris <briannorris@chromium.org>

[ Upstream commit 2fccf9e6050e0e3b8b4cd275d41daf7f7fa22804 ]

Otherwise we hit an unablanced enable-count when unbinding the DFI
device:

[ 1279.659119] ------------[ cut here ]------------
[ 1279.659179] WARNING: CPU: 2 PID: 5638 at drivers/devfreq/devfreq-event.c:360 devfreq_event_remove_edev+0x84/0x8c
...
[ 1279.659352] Hardware name: Google Kevin (DT)
[ 1279.659363] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
[ 1279.659371] pc : devfreq_event_remove_edev+0x84/0x8c
[ 1279.659380] lr : devm_devfreq_event_release+0x1c/0x28
...
[ 1279.659571] Call trace:
[ 1279.659582]  devfreq_event_remove_edev+0x84/0x8c
[ 1279.659590]  devm_devfreq_event_release+0x1c/0x28
[ 1279.659602]  release_nodes+0x1cc/0x244
[ 1279.659611]  devres_release_all+0x44/0x60
[ 1279.659621]  device_release_driver_internal+0x11c/0x1ac
[ 1279.659629]  device_driver_detach+0x20/0x2c
[ 1279.659641]  unbind_store+0x7c/0xb0
[ 1279.659650]  drv_attr_store+0x2c/0x40
[ 1279.659663]  sysfs_kf_write+0x44/0x58
[ 1279.659672]  kernfs_fop_write_iter+0xf4/0x190
[ 1279.659684]  vfs_write+0x2b0/0x2e4
[ 1279.659693]  ksys_write+0x80/0xec
[ 1279.659701]  __arm64_sys_write+0x24/0x30
[ 1279.659714]  el0_svc_common+0xf0/0x1d8
[ 1279.659724]  do_el0_svc_compat+0x28/0x3c
[ 1279.659738]  el0_svc_compat+0x10/0x1c
[ 1279.659746]  el0_sync_compat_handler+0xa8/0xcc
[ 1279.659758]  el0_sync_compat+0x188/0x1c0
[ 1279.659768] ---[ end trace cec200e5094155b4 ]---

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/devfreq/rk3399_dmc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/devfreq/rk3399_dmc.c b/drivers/devfreq/rk3399_dmc.c
index 293857ebfd75..538e8dc74f40 100644
--- a/drivers/devfreq/rk3399_dmc.c
+++ b/drivers/devfreq/rk3399_dmc.c
@@ -477,6 +477,8 @@ static int rk3399_dmcfreq_remove(struct platform_device *pdev)
 {
 	struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(&pdev->dev);
 
+	devfreq_event_disable_edev(dmcfreq->edev);
+
 	/*
 	 * Before remove the opp table we need to unregister the opp notifier.
 	 */
-- 
2.35.1

[PATCH AUTOSEL 5.15 23/37] cpufreq: Avoid unnecessary frequency updates due to mismatch

[Sasha Levin]

From: Viresh Kumar <viresh.kumar@linaro.org>

[ Upstream commit f55ae08c89873e140c7cac2a7fa161d31a0d60cf ]

For some platforms, the frequency returned by hardware may be slightly
different from what is provided in the frequency table. For example,
hardware may return 499 MHz instead of 500 MHz. In such cases it is
better to avoid getting into unnecessary frequency updates, as we may
end up switching policy->cur between the two and sending unnecessary
pre/post update notifications, etc.

This patch has chosen allows the hardware frequency and table frequency
to deviate by 1 MHz for now, we may want to increase it a bit later on
if someone still complains.

Reported-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Jia-wei Chang <jia-wei.chang@mediatek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/cpufreq/cpufreq.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index eeac6d809229..cddf7e13c232 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -28,6 +28,7 @@
 #include <linux/suspend.h>
 #include <linux/syscore_ops.h>
 #include <linux/tick.h>
+#include <linux/units.h>
 #include <trace/events/power.h>
 
 static LIST_HEAD(cpufreq_policy_list);
@@ -1701,6 +1702,16 @@ static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, b
 		return new_freq;
 
 	if (policy->cur != new_freq) {
+		/*
+		 * For some platforms, the frequency returned by hardware may be
+		 * slightly different from what is provided in the frequency
+		 * table, for example hardware may return 499 MHz instead of 500
+		 * MHz. In such cases it is better to avoid getting into
+		 * unnecessary frequency updates.
+		 */
+		if (abs(policy->cur - new_freq) < HZ_PER_MHZ)
+			return policy->cur;
+
 		cpufreq_out_of_sync(policy, new_freq);
 		if (update)
 			schedule_work(&policy->update);
-- 
2.35.1