2024-06-13 16:45:55

by Sibi Sankar

[permalink] [raw]
Subject: [PATCH] soc: qcom: icc-bwmon: Fix refcount imbalance seen during bwmon_remove

The following warning is seen during bwmon_remove due to refcount
imbalance, fix this by releasing the OPPs after use.

Logs:
WARNING: at drivers/opp/core.c:1640 _opp_table_kref_release+0x150/0x158
Hardware name: Qualcomm Technologies, Inc. X1E80100 CRD (DT)
...
Call trace:
_opp_table_kref_release+0x150/0x158
dev_pm_opp_remove_table+0x100/0x1b4
devm_pm_opp_of_table_release+0x10/0x1c
devm_action_release+0x14/0x20
devres_release_all+0xa4/0x104
device_unbind_cleanup+0x18/0x60
device_release_driver_internal+0x1ec/0x228
driver_detach+0x50/0x98
bus_remove_driver+0x6c/0xbc
driver_unregister+0x30/0x60
platform_driver_unregister+0x14/0x20
bwmon_driver_exit+0x18/0x524 [icc_bwmon]
__arm64_sys_delete_module+0x184/0x264
invoke_syscall+0x48/0x118
el0_svc_common.constprop.0+0xc8/0xe8
do_el0_svc+0x20/0x2c
el0_svc+0x34/0xdc
el0t_64_sync_handler+0x13c/0x158
el0t_64_sync+0x190/0x194
--[ end trace 0000000000000000 ]---

Fixes: 0276f69f13e2 ("soc: qcom: icc-bwmon: Set default thresholds dynamically")
Fixes: b9c2ae6cac40 ("soc: qcom: icc-bwmon: Add bandwidth monitoring driver")
Signed-off-by: Sibi Sankar <[email protected]>
---
drivers/soc/qcom/icc-bwmon.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/qcom/icc-bwmon.c b/drivers/soc/qcom/icc-bwmon.c
index fb323b3364db..ecddb60bd665 100644
--- a/drivers/soc/qcom/icc-bwmon.c
+++ b/drivers/soc/qcom/icc-bwmon.c
@@ -565,7 +565,7 @@ static void bwmon_start(struct icc_bwmon *bwmon)
int window;

/* No need to check for errors, as this must have succeeded before. */
- dev_pm_opp_find_bw_ceil(bwmon->dev, &bw_low, 0);
+ dev_pm_opp_put(dev_pm_opp_find_bw_ceil(bwmon->dev, &bw_low, 0));

bwmon_clear_counters(bwmon, true);

@@ -772,11 +772,13 @@ static int bwmon_probe(struct platform_device *pdev)
opp = dev_pm_opp_find_bw_floor(dev, &bwmon->max_bw_kbps, 0);
if (IS_ERR(opp))
return dev_err_probe(dev, PTR_ERR(opp), "failed to find max peak bandwidth\n");
+ dev_pm_opp_put(opp);

bwmon->min_bw_kbps = 0;
opp = dev_pm_opp_find_bw_ceil(dev, &bwmon->min_bw_kbps, 0);
if (IS_ERR(opp))
return dev_err_probe(dev, PTR_ERR(opp), "failed to find min peak bandwidth\n");
+ dev_pm_opp_put(opp);

bwmon->dev = dev;

--
2.34.1



2024-06-13 17:30:20

by Konrad Dybcio

[permalink] [raw]
Subject: Re: [PATCH] soc: qcom: icc-bwmon: Fix refcount imbalance seen during bwmon_remove



On 6/13/24 18:45, Sibi Sankar wrote:
> The following warning is seen during bwmon_remove due to refcount
> imbalance, fix this by releasing the OPPs after use.
>
> Logs:
> WARNING: at drivers/opp/core.c:1640 _opp_table_kref_release+0x150/0x158
> Hardware name: Qualcomm Technologies, Inc. X1E80100 CRD (DT)
> ...
> Call trace:
> _opp_table_kref_release+0x150/0x158
> dev_pm_opp_remove_table+0x100/0x1b4
> devm_pm_opp_of_table_release+0x10/0x1c
> devm_action_release+0x14/0x20
> devres_release_all+0xa4/0x104
> device_unbind_cleanup+0x18/0x60
> device_release_driver_internal+0x1ec/0x228
> driver_detach+0x50/0x98
> bus_remove_driver+0x6c/0xbc
> driver_unregister+0x30/0x60
> platform_driver_unregister+0x14/0x20
> bwmon_driver_exit+0x18/0x524 [icc_bwmon]
> __arm64_sys_delete_module+0x184/0x264
> invoke_syscall+0x48/0x118
> el0_svc_common.constprop.0+0xc8/0xe8
> do_el0_svc+0x20/0x2c
> el0_svc+0x34/0xdc
> el0t_64_sync_handler+0x13c/0x158
> el0t_64_sync+0x190/0x194
> --[ end trace 0000000000000000 ]---
>
> Fixes: 0276f69f13e2 ("soc: qcom: icc-bwmon: Set default thresholds dynamically")
> Fixes: b9c2ae6cac40 ("soc: qcom: icc-bwmon: Add bandwidth monitoring driver")
> Signed-off-by: Sibi Sankar <[email protected]>
> ---

Reviewed-by: Konrad Dybcio <[email protected]>

Konrad

2024-06-13 17:30:53

by Konrad Dybcio

[permalink] [raw]
Subject: Re: [PATCH] soc: qcom: icc-bwmon: Fix refcount imbalance seen during bwmon_remove



On 6/13/24 19:29, Konrad Dybcio wrote:
>
>
> On 6/13/24 18:45, Sibi Sankar wrote:
>> The following warning is seen during bwmon_remove due to refcount
>> imbalance, fix this by releasing the OPPs after use.
>>
>> Logs:
>> WARNING: at drivers/opp/core.c:1640 _opp_table_kref_release+0x150/0x158
>> Hardware name: Qualcomm Technologies, Inc. X1E80100 CRD (DT)
>> ...
>> Call trace:
>> _opp_table_kref_release+0x150/0x158
>> dev_pm_opp_remove_table+0x100/0x1b4
>> devm_pm_opp_of_table_release+0x10/0x1c
>> devm_action_release+0x14/0x20
>> devres_release_all+0xa4/0x104
>> device_unbind_cleanup+0x18/0x60
>> device_release_driver_internal+0x1ec/0x228
>> driver_detach+0x50/0x98
>> bus_remove_driver+0x6c/0xbc
>> driver_unregister+0x30/0x60
>> platform_driver_unregister+0x14/0x20
>> bwmon_driver_exit+0x18/0x524 [icc_bwmon]
>> __arm64_sys_delete_module+0x184/0x264
>> invoke_syscall+0x48/0x118
>> el0_svc_common.constprop.0+0xc8/0xe8
>> do_el0_svc+0x20/0x2c
>> el0_svc+0x34/0xdc
>> el0t_64_sync_handler+0x13c/0x158
>> el0t_64_sync+0x190/0x194
>> --[ end trace 0000000000000000 ]---
>>
>> Fixes: 0276f69f13e2 ("soc: qcom: icc-bwmon: Set default thresholds dynamically")
>> Fixes: b9c2ae6cac40 ("soc: qcom: icc-bwmon: Add bandwidth monitoring driver")
>> Signed-off-by: Sibi Sankar <[email protected]>
>> ---
>
> Reviewed-by: Konrad Dybcio <[email protected]>

Cc: [email protected]

Konrad