[PATCH v4 1/2] drm/panfrost: Add missing OPP table refcnt decremental

[PATCH v4 1/2] drm/panfrost: Add missing OPP table refcnt decremental

[Adrián Larumbe]

Commit f11b0417eec2 ("drm/panfrost: Add fdinfo support GPU load metrics")
retrieves the OPP for the maximum device clock frequency, but forgets to
keep the reference count balanced by putting the returned OPP object. This
eventually leads to an OPP core warning when removing the device.

Fix it by putting OPP objects as many times as they're retrieved.

Also remove an unnecessary whitespace.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Fixes: f11b0417eec2 ("drm/panfrost: Add fdinfo support GPU load metrics")
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
---
 drivers/gpu/drm/panfrost/panfrost_devfreq.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
index 2d30da38c2c3..3385fd3ef41a 100644
--- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
+++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
@@ -38,7 +38,7 @@ static int panfrost_devfreq_target(struct device *dev, unsigned long *freq,
 		return PTR_ERR(opp);
 	dev_pm_opp_put(opp);
 
-	err =  dev_pm_opp_set_rate(dev, *freq);
+	err = dev_pm_opp_set_rate(dev, *freq);
 	if (!err)
 		ptdev->pfdevfreq.current_frequency = *freq;
 
@@ -182,6 +182,7 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
 	 * if any and will avoid a switch off by regulator_late_cleanup()
 	 */
 	ret = dev_pm_opp_set_opp(dev, opp);
+	dev_pm_opp_put(opp);
 	if (ret) {
 		DRM_DEV_ERROR(dev, "Couldn't set recommended OPP\n");
 		return ret;

base-commit: aadcf584583ca9833b4fb2140a4f437569ddbcd7
-- 
2.46.2

[PATCH v4 2/2] drm/panthor: Fix OPP refcnt leaks in devfreq initialisation

[Adrián Larumbe]

Rearrange lookup of recommended OPP for the Mali GPU device and its refcnt
decremental to make sure no OPP object leaks happen in the error path.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Fixes: fac9b22df4b1 ("drm/panthor: Add the devfreq logical block")
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
---
 drivers/gpu/drm/panthor/panthor_devfreq.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_devfreq.c b/drivers/gpu/drm/panthor/panthor_devfreq.c
index 9d0f891b9b53..ecc7a52bd688 100644
--- a/drivers/gpu/drm/panthor/panthor_devfreq.c
+++ b/drivers/gpu/drm/panthor/panthor_devfreq.c
@@ -163,13 +163,6 @@ int panthor_devfreq_init(struct panthor_device *ptdev)
 
 	cur_freq = clk_get_rate(ptdev->clks.core);
 
-	opp = devfreq_recommended_opp(dev, &cur_freq, 0);
-	if (IS_ERR(opp))
-		return PTR_ERR(opp);
-
-	panthor_devfreq_profile.initial_freq = cur_freq;
-	ptdev->current_frequency = cur_freq;
-
 	/* Regulator coupling only takes care of synchronizing/balancing voltage
 	 * updates, but the coupled regulator needs to be enabled manually.
 	 *
@@ -200,18 +193,24 @@ int panthor_devfreq_init(struct panthor_device *ptdev)
 		return ret;
 	}
 
+	opp = devfreq_recommended_opp(dev, &cur_freq, 0);
+	if (IS_ERR(opp))
+		return PTR_ERR(opp);
+
+	panthor_devfreq_profile.initial_freq = cur_freq;
+	ptdev->current_frequency = cur_freq;
+
 	/*
 	 * Set the recommend OPP this will enable and configure the regulator
 	 * if any and will avoid a switch off by regulator_late_cleanup()
 	 */
 	ret = dev_pm_opp_set_opp(dev, opp);
+	dev_pm_opp_put(opp);
 	if (ret) {
 		DRM_DEV_ERROR(dev, "Couldn't set recommended OPP\n");
 		return ret;
 	}
 
-	dev_pm_opp_put(opp);
-
 	/* Find the fastest defined rate  */
 	opp = dev_pm_opp_find_freq_floor(dev, &freq);
 	if (IS_ERR(opp))
-- 
2.46.2

Re: [PATCH v4 1/2] drm/panfrost: Add missing OPP table refcnt decremental

[Steven Price]

On 05/11/2024 20:54, Adrián Larumbe wrote:
> Commit f11b0417eec2 ("drm/panfrost: Add fdinfo support GPU load metrics")
> retrieves the OPP for the maximum device clock frequency, but forgets to
> keep the reference count balanced by putting the returned OPP object. This
> eventually leads to an OPP core warning when removing the device.
> 
> Fix it by putting OPP objects as many times as they're retrieved.
> 
> Also remove an unnecessary whitespace.
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
> Fixes: f11b0417eec2 ("drm/panfrost: Add fdinfo support GPU load metrics")
> Reviewed-by: Steven Price <steven.price@arm.com>
> Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

Both pushed to drm-misc-next.

Thanks,
Steve

> ---
>  drivers/gpu/drm/panfrost/panfrost_devfreq.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> index 2d30da38c2c3..3385fd3ef41a 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> @@ -38,7 +38,7 @@ static int panfrost_devfreq_target(struct device *dev, unsigned long *freq,
>  		return PTR_ERR(opp);
>  	dev_pm_opp_put(opp);
>  
> -	err =  dev_pm_opp_set_rate(dev, *freq);
> +	err = dev_pm_opp_set_rate(dev, *freq);
>  	if (!err)
>  		ptdev->pfdevfreq.current_frequency = *freq;
>  
> @@ -182,6 +182,7 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
>  	 * if any and will avoid a switch off by regulator_late_cleanup()
>  	 */
>  	ret = dev_pm_opp_set_opp(dev, opp);
> +	dev_pm_opp_put(opp);
>  	if (ret) {
>  		DRM_DEV_ERROR(dev, "Couldn't set recommended OPP\n");
>  		return ret;
> 
> base-commit: aadcf584583ca9833b4fb2140a4f437569ddbcd7