Re: [PATCH AUTOSEL 4.19 075/128] PM / devfreq: passive: Use non-devm notifiers

2019-10-01 Thread Sasha Levin 

On Mon, Sep 23, 2019 at 08:38:53PM +, Leonard Crestez wrote:

On 22.09.2019 21:56, Sasha Levin wrote:

From: Leonard Crestez 

[ Upstream commit 0ef7c7cce43f6ecc2b96d447e69b2900a9655f7c ]


This will introduce an "unused variable warning" unless you also
cherry-pick commit 0465814831a9 ("PM / devfreq: passive: fix compiler
warning").


I've grabbed it too, thanks!

--
Thanks,
Sasha

Re: [PATCH AUTOSEL 4.19 075/128] PM / devfreq: passive: Use non-devm notifiers

2019-09-23 Thread Leonard Crestez 
On 22.09.2019 21:56, Sasha Levin wrote:
> From: Leonard Crestez 
> 
> [ Upstream commit 0ef7c7cce43f6ecc2b96d447e69b2900a9655f7c ]

This will introduce an "unused variable warning" unless you also 
cherry-pick commit 0465814831a9 ("PM / devfreq: passive: fix compiler 
warning").

> The devfreq passive governor registers and unregisters devfreq
> transition notifiers on DEVFREQ_GOV_START/GOV_STOP using devm wrappers.
> 
> If devfreq itself is registered with devm then a warning is triggered on
> rmmod from devm_devfreq_unregister_notifier. Call stack looks like this:
> 
>   devm_devfreq_unregister_notifier+0x30/0x40
>   devfreq_passive_event_handler+0x4c/0x88
>   devfreq_remove_device.part.8+0x6c/0x9c
>   devm_devfreq_dev_release+0x18/0x20
>   release_nodes+0x1b0/0x220
>   devres_release_all+0x78/0x84
>   device_release_driver_internal+0x100/0x1c0
>   driver_detach+0x4c/0x90
>   bus_remove_driver+0x7c/0xd0
>   driver_unregister+0x2c/0x58
>   platform_driver_unregister+0x10/0x18
>   imx_devfreq_platdrv_exit+0x14/0xd40 [imx_devfreq]
> 
> This happens because devres_release_all will first remove all the nodes
> into a separate todo list so the nested devres_release from
> devm_devfreq_unregister_notifier won't find anything.
> 
> Fix the warning by calling the non-devm APIS for frequency notification.
> Using devm wrappers is not actually useful for a governor anyway: it
> relies on the devfreq core to correctly match the GOV_START/GOV_STOP
> notifications.
> 
> Fixes: 996133119f57 ("PM / devfreq: Add new passive governor")
> Signed-off-by: Leonard Crestez 
> Acked-by: Chanwoo Choi 
> Signed-off-by: MyungJoo Ham 
> Signed-off-by: Sasha Levin 
> ---
>   drivers/devfreq/governor_passive.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/devfreq/governor_passive.c 
> b/drivers/devfreq/governor_passive.c
> index 3bc29acbd54e8..22fd41b4c1098 100644
> --- a/drivers/devfreq/governor_passive.c
> +++ b/drivers/devfreq/governor_passive.c
> @@ -168,12 +168,12 @@ static int devfreq_passive_event_handler(struct devfreq 
> *devfreq,
>   p_data->this = devfreq;
>   
>   nb->notifier_call = devfreq_passive_notifier_call;
> - ret = devm_devfreq_register_notifier(dev, parent, nb,
> + ret = devfreq_register_notifier(parent, nb,
>   DEVFREQ_TRANSITION_NOTIFIER);
>   break;
>   case DEVFREQ_GOV_STOP:
> - devm_devfreq_unregister_notifier(dev, parent, nb,
> - DEVFREQ_TRANSITION_NOTIFIER);
> + WARN_ON(devfreq_unregister_notifier(parent, nb,
> + DEVFREQ_TRANSITION_NOTIFIER));
>   break;
>   default:
>   break;
>

[PATCH AUTOSEL 4.19 075/128] PM / devfreq: passive: Use non-devm notifiers

2019-09-22 Thread Sasha Levin 
From: Leonard Crestez 

[ Upstream commit 0ef7c7cce43f6ecc2b96d447e69b2900a9655f7c ]

The devfreq passive governor registers and unregisters devfreq
transition notifiers on DEVFREQ_GOV_START/GOV_STOP using devm wrappers.

If devfreq itself is registered with devm then a warning is triggered on
rmmod from devm_devfreq_unregister_notifier. Call stack looks like this:

devm_devfreq_unregister_notifier+0x30/0x40
devfreq_passive_event_handler+0x4c/0x88
devfreq_remove_device.part.8+0x6c/0x9c
devm_devfreq_dev_release+0x18/0x20
release_nodes+0x1b0/0x220
devres_release_all+0x78/0x84
device_release_driver_internal+0x100/0x1c0
driver_detach+0x4c/0x90
bus_remove_driver+0x7c/0xd0
driver_unregister+0x2c/0x58
platform_driver_unregister+0x10/0x18
imx_devfreq_platdrv_exit+0x14/0xd40 [imx_devfreq]

This happens because devres_release_all will first remove all the nodes
into a separate todo list so the nested devres_release from
devm_devfreq_unregister_notifier won't find anything.

Fix the warning by calling the non-devm APIS for frequency notification.
Using devm wrappers is not actually useful for a governor anyway: it
relies on the devfreq core to correctly match the GOV_START/GOV_STOP
notifications.

Fixes: 996133119f57 ("PM / devfreq: Add new passive governor")
Signed-off-by: Leonard Crestez 
Acked-by: Chanwoo Choi 
Signed-off-by: MyungJoo Ham 
Signed-off-by: Sasha Levin 
---
 drivers/devfreq/governor_passive.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/devfreq/governor_passive.c 
b/drivers/devfreq/governor_passive.c
index 3bc29acbd54e8..22fd41b4c1098 100644
--- a/drivers/devfreq/governor_passive.c
+++ b/drivers/devfreq/governor_passive.c
@@ -168,12 +168,12 @@ static int devfreq_passive_event_handler(struct devfreq 
*devfreq,
p_data->this = devfreq;
 
nb->notifier_call = devfreq_passive_notifier_call;
-   ret = devm_devfreq_register_notifier(dev, parent, nb,
+   ret = devfreq_register_notifier(parent, nb,
DEVFREQ_TRANSITION_NOTIFIER);
break;
case DEVFREQ_GOV_STOP:
-   devm_devfreq_unregister_notifier(dev, parent, nb,
-   DEVFREQ_TRANSITION_NOTIFIER);
+   WARN_ON(devfreq_unregister_notifier(parent, nb,
+   DEVFREQ_TRANSITION_NOTIFIER));
break;
default:
break;
-- 
2.20.1