[PATCH] media: qcom: camss: fix VFE pm domain off

[PATCH] media: qcom: camss: fix VFE pm domain off

[Barnabás Czémán]

Fix NULL pointer check before device_link_del
is called.

Fixes: eb73facec2c2 ("media: qcom: camss: Use common VFE pm_domain_on/pm_domain_off where applicable")
Signed-off-by: Barnabás Czémán <barnabas.czeman@mainlining.org>
---
 drivers/media/platform/qcom/camss/camss-vfe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/platform/qcom/camss/camss-vfe.c b/drivers/media/platform/qcom/camss/camss-vfe.c
index 80a62ba11295042802cbaec617fb87c492ea6a55..1bf1473331f63b9ab106d21ea263c84d851c8a31 100644
--- a/drivers/media/platform/qcom/camss/camss-vfe.c
+++ b/drivers/media/platform/qcom/camss/camss-vfe.c
@@ -595,7 +595,7 @@ void vfe_isr_reset_ack(struct vfe_device *vfe)
  */
 void vfe_pm_domain_off(struct vfe_device *vfe)
 {
-	if (!vfe->genpd)
+	if (!vfe->genpd_link)
 		return;
 
 	device_link_del(vfe->genpd_link);

---
base-commit: decc701f41d07481893fdea942c0ac6b226e84cd
change-id: 20241122-vfe_pm_domain_off-c57008e54167

Best regards,
-- 
Barnabás Czémán <barnabas.czeman@mainlining.org>

Re: [PATCH] media: qcom: camss: fix VFE pm domain off

[Yassine Oudjana]

On 22/11/2024 5:06 am, Barnabás Czémán wrote:
> Fix NULL pointer check before device_link_del
> is called.
> 
> Fixes: eb73facec2c2 ("media: qcom: camss: Use common VFE pm_domain_on/pm_domain_off where applicable")
> Signed-off-by: Barnabás Czémán <barnabas.czeman@mainlining.org>
> ---
>   drivers/media/platform/qcom/camss/camss-vfe.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> 
> ---
> base-commit: decc701f41d07481893fdea942c0ac6b226e84cd
> change-id: 20241122-vfe_pm_domain_off-c57008e54167
> 
> Best regards,
> 
> diff --git a/drivers/media/platform/qcom/camss/camss-vfe.c b/drivers/media/platform/qcom/camss/camss-vfe.c
> index 80a62ba11295042802cbaec617fb87c492ea6a55..1bf1473331f63b9ab106d21ea263c84d851c8a31 100644
> --- a/drivers/media/platform/qcom/camss/camss-vfe.c
> +++ b/drivers/media/platform/qcom/camss/camss-vfe.c
> @@ -595,7 +595,7 @@ void vfe_isr_reset_ack(struct vfe_device *vfe)
>    */
>   void vfe_pm_domain_off(struct vfe_device *vfe)
>   {
> -	if (!vfe->genpd)
> +	if (!vfe->genpd_link)
>   		return;
>   
>   	device_link_del(vfe->genpd_link);

Tested-by: Yassine Oudjana <y.oudjana@protonmail.com>

Re: [PATCH] media: qcom: camss: fix VFE pm domain off

[Vladimir Zapolskiy]

On 11/27/24 12:01, Yassine Oudjana wrote:
> On 22/11/2024 5:06 am, Barnabás Czémán wrote:
>> Fix NULL pointer check before device_link_del
>> is called.

The intention is clear, but the context of the change is completely lost.

>> Fixes: eb73facec2c2 ("media: qcom: camss: Use common VFE pm_domain_on/pm_domain_off where applicable")

It's invalid, the change is not a fix.

>> Signed-off-by: Barnabás Czémán <barnabas.czeman@mainlining.org>
>> ---
>>    drivers/media/platform/qcom/camss/camss-vfe.c | 2 +-
>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>
>>
>> ---
>> base-commit: decc701f41d07481893fdea942c0ac6b226e84cd
>> change-id: 20241122-vfe_pm_domain_off-c57008e54167
>>
>> Best regards,
>>
>> diff --git a/drivers/media/platform/qcom/camss/camss-vfe.c b/drivers/media/platform/qcom/camss/camss-vfe.c
>> index 80a62ba11295042802cbaec617fb87c492ea6a55..1bf1473331f63b9ab106d21ea263c84d851c8a31 100644
>> --- a/drivers/media/platform/qcom/camss/camss-vfe.c
>> +++ b/drivers/media/platform/qcom/camss/camss-vfe.c
>> @@ -595,7 +595,7 @@ void vfe_isr_reset_ack(struct vfe_device *vfe)
>>     */
>>    void vfe_pm_domain_off(struct vfe_device *vfe)
>>    {
>> -	if (!vfe->genpd)
>> +	if (!vfe->genpd_link)
>>    		return;
>>    
>>    	device_link_del(vfe->genpd_link);
> 
> Tested-by: Yassine Oudjana <y.oudjana@protonmail.com>
> 

The change is useless and it shall be dropped.

--
Best wishes,
Vladimir

Re: [PATCH] media: qcom: camss: fix VFE pm domain off

[barnabas.czeman]

On 2024-11-28 10:10, Vladimir Zapolskiy wrote:
> On 11/27/24 12:01, Yassine Oudjana wrote:
>> On 22/11/2024 5:06 am, Barnabás Czémán wrote:
>>> Fix NULL pointer check before device_link_del
>>> is called.
> 
> The intention is clear, but the context of the change is completely 
> lost.
> 
>>> Fixes: eb73facec2c2 ("media: qcom: camss: Use common VFE 
>>> pm_domain_on/pm_domain_off where applicable")
> 
> It's invalid, the change is not a fix.
I don't agree this patch is fixing NULL pointer dereference.

[   92.989120] Unable to handle kernel NULL pointer dereference at 
virtual address 000000000000032c
[   92.989170] Mem abort info:
[   92.989186]   ESR = 0x0000000096000004
[   92.989203]   EC = 0x25: DABT (current EL), IL = 32 bits
[   92.989221]   SET = 0, FnV = 0
[   92.989237]   EA = 0, S1PTW = 0
[   92.989253]   FSC = 0x04: level 0 translation fault
[   92.989270] Data abort info:
[   92.989284]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[   92.989300]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   92.989317]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   92.989335] user pgtable: 4k pages, 48-bit VAs, pgdp=00000001218a8000
[   92.989354] [000000000000032c] pgd=0000000000000000, 
p4d=0000000000000000
[   92.989389] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[   92.989408] Modules linked in: q6afe_dai q6asm_dai q6routing q6adm 
q6asm q6afe snd_q6dsp_common panel_lgphilips_sw43101 q6core venus_enc 
venus_dec videobuf2_dma_contig imx318 ak7375 snd_soc_wcd9335 
regmap_slimbus snd_soc_wcd_classh apr snd_soc_apq8096 
snd_soc_qcom_common snd_soc_core qcom_camss msm v4l2_fwnode snd_compress 
ath10k_pci v4l2_async ath10k_core snd_pcm nxp_nci_i2c drm_exec nxp_nci 
venus_core videobuf2_dma_sg snd_timer ath v4l2_mem2mem videobuf2_memops 
mac80211 drm_dp_aux_bus snd gpu_sched nci videobuf2_v4l2 libarc4 
soundcore videodev nfc slim_qcom_ngd_ctrl drm_display_helper hci_uart 
pdr_interface videobuf2_common btqca drm_kms_helper slimbus i2c_qcom_cci 
bluetooth mc qcom_q6v5_pas qcom_q6v5_mss qcom_pil_info qcom_q6v5 
qcom_sysmon qcom_common qmi_helpers mdt_loader socinfo rmtfs_mem 
pwm_ir_tx cfg80211 rfkill zram zsmalloc atmel_mxt_ts drm 
drm_panel_orientation_quirks dm_mod ip_tables
[   92.989981] CPU: 2 PID: 1365 Comm: pool-megapixels Not tainted 
6.9.0-rc3+ #10
[   92.990003] Hardware name: Xiaomi Mi Note 2 (DT)
[   92.990020] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS 
BTYPE=--)
[   92.990042] pc : device_link_put_kref+0xc/0xb8
[   92.990071] lr : device_link_del+0x30/0x48
[   92.990089] sp : ffff80008a5db9d0
[   92.990105] x29: ffff80008a5db9d0 x28: 0000000000000001 x27: 
0000000000000000
[   92.990143] x26: 0000000000000000 x25: ffff0000e79d9100 x24: 
ffff0000e79d9500
[   92.990180] x23: ffff0000943f8568 x22: 00000000ffffffff x21: 
0000000000000000
[   92.990217] x20: 0000000000000000 x19: ffff800081352498 x18: 
0000000000000000
[   92.990253] x17: 0000000000000000 x16: 0000000000000000 x15: 
0000000000000168
[   92.990288] x14: 0000000000000000 x13: 0000000000000191 x12: 
ffff800081259d58
[   92.990324] x11: 0000000000000001 x10: 0000000000000a60 x9 : 
ffff80008a5db7e0
[   92.990359] x8 : ffff0000e79d9bc0 x7 : 0000000000000004 x6 : 
0000000000000190
[   92.990396] x5 : 0000000000000057 x4 : 0000000000000000 x3 : 
0000000000000000
[   92.990430] x2 : ffff0000e79d9100 x1 : 0000000000000000 x0 : 
0000000000000000
[   92.990466] Call trace:
[   92.990482]  device_link_put_kref+0xc/0xb8
[   92.990503]  device_link_del+0x30/0x48
[   92.990522]  vfe_pm_domain_off+0x24/0x38 [qcom_camss]
[   92.990566]  vfe_put+0x9c/0xd0 [qcom_camss]
[   92.990601]  vfe_set_power+0x48/0x58 [qcom_camss]
[   92.990636]  pipeline_pm_power_one+0x154/0x158 [videodev]
[   92.990683]  pipeline_pm_power+0x74/0xfc [videodev]
[   92.990720]  v4l2_pipeline_pm_use+0x54/0x90 [videodev]
[   92.990757]  v4l2_pipeline_pm_put+0x14/0x34 [videodev]
[   92.990793]  video_release+0x2c/0x44 [qcom_camss]
[   92.990828]  v4l2_release+0xe4/0xec [videodev]
[   92.990865]  __fput+0x78/0x2c4
[   92.990892]  ____fput+0x10/0x1c
[   92.990915]  task_work_run+0x74/0xcc
[   92.990936]  do_exit+0x2c4/0x8fc
[   92.990961]  do_group_exit+0x34/0x90
[   92.990984]  get_signal+0x870/0x880
[   92.991008]  do_signal+0x8c/0x12b8
[   92.991034]  do_notify_resume+0xc8/0x140
[   92.991054]  el0_svc+0xc4/0xd8
[   92.991079]  el0t_64_sync_handler+0x120/0x12c
[   92.991102]  el0t_64_sync+0x190/0x194
[   92.991127] Code: 17ffffda d503233f a9bf7bfd 910003fd (b9432c01)
[   92.991150] ---[ end trace 0000000000000000 ]---

Here is a similar example from camss:
static void camss_genpd_cleanup(struct camss *camss)
{
         if (camss->genpd_num == 1)
                 return;

         camss_genpd_subdevice_cleanup(camss);

         if (camss->genpd_link)
                 device_link_del(camss->genpd_link);

         dev_pm_domain_detach(camss->genpd, true);
}
> 
>>> Signed-off-by: Barnabás Czémán <barnabas.czeman@mainlining.org>
>>> ---
>>>    drivers/media/platform/qcom/camss/camss-vfe.c | 2 +-
>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>> 
>>> 
>>> ---
>>> base-commit: decc701f41d07481893fdea942c0ac6b226e84cd
>>> change-id: 20241122-vfe_pm_domain_off-c57008e54167
>>> 
>>> Best regards,
>>> 
>>> diff --git a/drivers/media/platform/qcom/camss/camss-vfe.c 
>>> b/drivers/media/platform/qcom/camss/camss-vfe.c
>>> index 
>>> 80a62ba11295042802cbaec617fb87c492ea6a55..1bf1473331f63b9ab106d21ea263c84d851c8a31 
>>> 100644
>>> --- a/drivers/media/platform/qcom/camss/camss-vfe.c
>>> +++ b/drivers/media/platform/qcom/camss/camss-vfe.c
>>> @@ -595,7 +595,7 @@ void vfe_isr_reset_ack(struct vfe_device *vfe)
>>>     */
>>>    void vfe_pm_domain_off(struct vfe_device *vfe)
>>>    {
>>> -	if (!vfe->genpd)
>>> +	if (!vfe->genpd_link)
>>>    		return;
>>>       	device_link_del(vfe->genpd_link);
>> 
>> Tested-by: Yassine Oudjana <y.oudjana@protonmail.com>
>> 
> 
> The change is useless and it shall be dropped.
> 
> --
> Best wishes,
> Vladimir

Re: [PATCH] media: qcom: camss: fix VFE pm domain off

[Bryan O'Donoghue]

On 28/11/2024 10:27, barnabas.czeman@mainlining.org wrote:
> On 2024-11-28 10:10, Vladimir Zapolskiy wrote:
>> On 11/27/24 12:01, Yassine Oudjana wrote:
>>> On 22/11/2024 5:06 am, Barnabás Czémán wrote:
>>>> Fix NULL pointer check before device_link_del
>>>> is called.
>>
>> The intention is clear, but the context of the change is completely lost.
>>
>>>> Fixes: eb73facec2c2 ("media: qcom: camss: Use common VFE 
>>>> pm_domain_on/pm_domain_off where applicable")
>>
>> It's invalid, the change is not a fix.
> I don't agree this patch is fixing NULL pointer dereference.
> 
> [   92.989120] Unable to handle kernel NULL pointer dereference at 
> virtual address 000000000000032c
> [   92.989170] Mem abort info:
> [   92.989186]   ESR = 0x0000000096000004
> [   92.989203]   EC = 0x25: DABT (current EL), IL = 32 bits
> [   92.989221]   SET = 0, FnV = 0
> [   92.989237]   EA = 0, S1PTW = 0
> [   92.989253]   FSC = 0x04: level 0 translation fault
> [   92.989270] Data abort info:
> [   92.989284]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> [   92.989300]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> [   92.989317]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [   92.989335] user pgtable: 4k pages, 48-bit VAs, pgdp=00000001218a8000
> [   92.989354] [000000000000032c] pgd=0000000000000000, 
> p4d=0000000000000000
> [   92.989389] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
> [   92.989408] Modules linked in: q6afe_dai q6asm_dai q6routing q6adm 
> q6asm q6afe snd_q6dsp_common panel_lgphilips_sw43101 q6core venus_enc 
> venus_dec videobuf2_dma_contig imx318 ak7375 snd_soc_wcd9335 
> regmap_slimbus snd_soc_wcd_classh apr snd_soc_apq8096 
> snd_soc_qcom_common snd_soc_core qcom_camss msm v4l2_fwnode snd_compress 
> ath10k_pci v4l2_async ath10k_core snd_pcm nxp_nci_i2c drm_exec nxp_nci 
> venus_core videobuf2_dma_sg snd_timer ath v4l2_mem2mem videobuf2_memops 
> mac80211 drm_dp_aux_bus snd gpu_sched nci videobuf2_v4l2 libarc4 
> soundcore videodev nfc slim_qcom_ngd_ctrl drm_display_helper hci_uart 
> pdr_interface videobuf2_common btqca drm_kms_helper slimbus i2c_qcom_cci 
> bluetooth mc qcom_q6v5_pas qcom_q6v5_mss qcom_pil_info qcom_q6v5 
> qcom_sysmon qcom_common qmi_helpers mdt_loader socinfo rmtfs_mem 
> pwm_ir_tx cfg80211 rfkill zram zsmalloc atmel_mxt_ts drm 
> drm_panel_orientation_quirks dm_mod ip_tables
> [   92.989981] CPU: 2 PID: 1365 Comm: pool-megapixels Not tainted 6.9.0- 
> rc3+ #10
> [   92.990003] Hardware name: Xiaomi Mi Note 2 (DT)
> [   92.990020] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS 
> BTYPE=--)
> [   92.990042] pc : device_link_put_kref+0xc/0xb8
> [   92.990071] lr : device_link_del+0x30/0x48
> [   92.990089] sp : ffff80008a5db9d0
> [   92.990105] x29: ffff80008a5db9d0 x28: 0000000000000001 x27: 
> 0000000000000000
> [   92.990143] x26: 0000000000000000 x25: ffff0000e79d9100 x24: 
> ffff0000e79d9500
> [   92.990180] x23: ffff0000943f8568 x22: 00000000ffffffff x21: 
> 0000000000000000
> [   92.990217] x20: 0000000000000000 x19: ffff800081352498 x18: 
> 0000000000000000
> [   92.990253] x17: 0000000000000000 x16: 0000000000000000 x15: 
> 0000000000000168
> [   92.990288] x14: 0000000000000000 x13: 0000000000000191 x12: 
> ffff800081259d58
> [   92.990324] x11: 0000000000000001 x10: 0000000000000a60 x9 : 
> ffff80008a5db7e0
> [   92.990359] x8 : ffff0000e79d9bc0 x7 : 0000000000000004 x6 : 
> 0000000000000190
> [   92.990396] x5 : 0000000000000057 x4 : 0000000000000000 x3 : 
> 0000000000000000
> [   92.990430] x2 : ffff0000e79d9100 x1 : 0000000000000000 x0 : 
> 0000000000000000
> [   92.990466] Call trace:
> [   92.990482]  device_link_put_kref+0xc/0xb8
> [   92.990503]  device_link_del+0x30/0x48
> [   92.990522]  vfe_pm_domain_off+0x24/0x38 [qcom_camss]
> [   92.990566]  vfe_put+0x9c/0xd0 [qcom_camss]
> [   92.990601]  vfe_set_power+0x48/0x58 [qcom_camss]
> [   92.990636]  pipeline_pm_power_one+0x154/0x158 [videodev]
> [   92.990683]  pipeline_pm_power+0x74/0xfc [videodev]
> [   92.990720]  v4l2_pipeline_pm_use+0x54/0x90 [videodev]
> [   92.990757]  v4l2_pipeline_pm_put+0x14/0x34 [videodev]
> [   92.990793]  video_release+0x2c/0x44 [qcom_camss]
> [   92.990828]  v4l2_release+0xe4/0xec [videodev]
> [   92.990865]  __fput+0x78/0x2c4
> [   92.990892]  ____fput+0x10/0x1c
> [   92.990915]  task_work_run+0x74/0xcc
> [   92.990936]  do_exit+0x2c4/0x8fc
> [   92.990961]  do_group_exit+0x34/0x90
> [   92.990984]  get_signal+0x870/0x880
> [   92.991008]  do_signal+0x8c/0x12b8
> [   92.991034]  do_notify_resume+0xc8/0x140
> [   92.991054]  el0_svc+0xc4/0xd8
> [   92.991079]  el0t_64_sync_handler+0x120/0x12c
> [   92.991102]  el0t_64_sync+0x190/0x194
> [   92.991127] Code: 17ffffda d503233f a9bf7bfd 910003fd (b9432c01)
> [   92.991150] ---[ end trace 0000000000000000 ]---
Please send a v2 of this patch including the backtrace, then add.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>

Re: [PATCH] media: qcom: camss: fix VFE pm domain off

[Vladimir Zapolskiy]

On 11/28/24 12:27, barnabas.czeman@mainlining.org wrote:
> On 2024-11-28 10:10, Vladimir Zapolskiy wrote:
>> On 11/27/24 12:01, Yassine Oudjana wrote:
>>> On 22/11/2024 5:06 am, Barnabás Czémán wrote:
>>>> Fix NULL pointer check before device_link_del
>>>> is called.
>>
>> The intention is clear, but the context of the change is completely
>> lost.
>>
>>>> Fixes: eb73facec2c2 ("media: qcom: camss: Use common VFE
>>>> pm_domain_on/pm_domain_off where applicable")
>>
>> It's invalid, the change is not a fix.
> I don't agree this patch is fixing NULL pointer dereference.
> 
> [   92.989120] Unable to handle kernel NULL pointer dereference at
> virtual address 000000000000032c
> [   92.989170] Mem abort info:
> [   92.989186]   ESR = 0x0000000096000004
> [   92.989203]   EC = 0x25: DABT (current EL), IL = 32 bits
> [   92.989221]   SET = 0, FnV = 0
> [   92.989237]   EA = 0, S1PTW = 0
> [   92.989253]   FSC = 0x04: level 0 translation fault
> [   92.989270] Data abort info:
> [   92.989284]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> [   92.989300]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> [   92.989317]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [   92.989335] user pgtable: 4k pages, 48-bit VAs, pgdp=00000001218a8000
> [   92.989354] [000000000000032c] pgd=0000000000000000,
> p4d=0000000000000000
> [   92.989389] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
> [   92.989408] Modules linked in: q6afe_dai q6asm_dai q6routing q6adm
> q6asm q6afe snd_q6dsp_common panel_lgphilips_sw43101 q6core venus_enc
> venus_dec videobuf2_dma_contig imx318 ak7375 snd_soc_wcd9335
> regmap_slimbus snd_soc_wcd_classh apr snd_soc_apq8096
> snd_soc_qcom_common snd_soc_core qcom_camss msm v4l2_fwnode snd_compress
> ath10k_pci v4l2_async ath10k_core snd_pcm nxp_nci_i2c drm_exec nxp_nci
> venus_core videobuf2_dma_sg snd_timer ath v4l2_mem2mem videobuf2_memops
> mac80211 drm_dp_aux_bus snd gpu_sched nci videobuf2_v4l2 libarc4
> soundcore videodev nfc slim_qcom_ngd_ctrl drm_display_helper hci_uart
> pdr_interface videobuf2_common btqca drm_kms_helper slimbus i2c_qcom_cci
> bluetooth mc qcom_q6v5_pas qcom_q6v5_mss qcom_pil_info qcom_q6v5
> qcom_sysmon qcom_common qmi_helpers mdt_loader socinfo rmtfs_mem
> pwm_ir_tx cfg80211 rfkill zram zsmalloc atmel_mxt_ts drm
> drm_panel_orientation_quirks dm_mod ip_tables
> [   92.989981] CPU: 2 PID: 1365 Comm: pool-megapixels Not tainted
> 6.9.0-rc3+ #10
> [   92.990003] Hardware name: Xiaomi Mi Note 2 (DT)
> [   92.990020] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS
> BTYPE=--)
> [   92.990042] pc : device_link_put_kref+0xc/0xb8
> [   92.990071] lr : device_link_del+0x30/0x48
> [   92.990089] sp : ffff80008a5db9d0
> [   92.990105] x29: ffff80008a5db9d0 x28: 0000000000000001 x27:
> 0000000000000000
> [   92.990143] x26: 0000000000000000 x25: ffff0000e79d9100 x24:
> ffff0000e79d9500
> [   92.990180] x23: ffff0000943f8568 x22: 00000000ffffffff x21:
> 0000000000000000
> [   92.990217] x20: 0000000000000000 x19: ffff800081352498 x18:
> 0000000000000000
> [   92.990253] x17: 0000000000000000 x16: 0000000000000000 x15:
> 0000000000000168
> [   92.990288] x14: 0000000000000000 x13: 0000000000000191 x12:
> ffff800081259d58
> [   92.990324] x11: 0000000000000001 x10: 0000000000000a60 x9 :
> ffff80008a5db7e0
> [   92.990359] x8 : ffff0000e79d9bc0 x7 : 0000000000000004 x6 :
> 0000000000000190
> [   92.990396] x5 : 0000000000000057 x4 : 0000000000000000 x3 :
> 0000000000000000
> [   92.990430] x2 : ffff0000e79d9100 x1 : 0000000000000000 x0 :
> 0000000000000000
> [   92.990466] Call trace:
> [   92.990482]  device_link_put_kref+0xc/0xb8
> [   92.990503]  device_link_del+0x30/0x48
> [   92.990522]  vfe_pm_domain_off+0x24/0x38 [qcom_camss]

vfe_pm_domain_off() shall not be called before vfe_pm_domain_on() call.

If vfe_pm_domain_on() is called and returns failure, then a media pipeline
shall not be started, and vfe_pm_domain_off() shall not be called.

If vfe_pm_domain_on() is called and returns success, then vfe->genpd_link
is not NULL.

Are there any perceptable flaws within the given above reasoning?

Since you've encountered a bug and taking the reasoning from above as
correct, I believe the bug is present somewhere else, and if so, it will
remain unfixed by this change.

> [   92.990566]  vfe_put+0x9c/0xd0 [qcom_camss]
> [   92.990601]  vfe_set_power+0x48/0x58 [qcom_camss]
> [   92.990636]  pipeline_pm_power_one+0x154/0x158 [videodev]
> [   92.990683]  pipeline_pm_power+0x74/0xfc [videodev]
> [   92.990720]  v4l2_pipeline_pm_use+0x54/0x90 [videodev]
> [   92.990757]  v4l2_pipeline_pm_put+0x14/0x34 [videodev]
> [   92.990793]  video_release+0x2c/0x44 [qcom_camss]
> [   92.990828]  v4l2_release+0xe4/0xec [videodev]

Please include the backtrace up to this point into the commit message.

--
Best wishes,
Vladimir

Re: [PATCH] media: qcom: camss: fix VFE pm domain off

[barnabas.czeman]

On 2024-11-28 14:22, Vladimir Zapolskiy wrote:
> On 11/28/24 12:27, barnabas.czeman@mainlining.org wrote:
>> On 2024-11-28 10:10, Vladimir Zapolskiy wrote:
>>> On 11/27/24 12:01, Yassine Oudjana wrote:
>>>> On 22/11/2024 5:06 am, Barnabás Czémán wrote:
>>>>> Fix NULL pointer check before device_link_del
>>>>> is called.
>>> 
>>> The intention is clear, but the context of the change is completely
>>> lost.
>>> 
>>>>> Fixes: eb73facec2c2 ("media: qcom: camss: Use common VFE
>>>>> pm_domain_on/pm_domain_off where applicable")
>>> 
>>> It's invalid, the change is not a fix.
>> I don't agree this patch is fixing NULL pointer dereference.
>> 
>> [   92.989120] Unable to handle kernel NULL pointer dereference at
>> virtual address 000000000000032c
>> [   92.989170] Mem abort info:
>> [   92.989186]   ESR = 0x0000000096000004
>> [   92.989203]   EC = 0x25: DABT (current EL), IL = 32 bits
>> [   92.989221]   SET = 0, FnV = 0
>> [   92.989237]   EA = 0, S1PTW = 0
>> [   92.989253]   FSC = 0x04: level 0 translation fault
>> [   92.989270] Data abort info:
>> [   92.989284]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
>> [   92.989300]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
>> [   92.989317]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
>> [   92.989335] user pgtable: 4k pages, 48-bit VAs, 
>> pgdp=00000001218a8000
>> [   92.989354] [000000000000032c] pgd=0000000000000000,
>> p4d=0000000000000000
>> [   92.989389] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
>> [   92.989408] Modules linked in: q6afe_dai q6asm_dai q6routing q6adm
>> q6asm q6afe snd_q6dsp_common panel_lgphilips_sw43101 q6core venus_enc
>> venus_dec videobuf2_dma_contig imx318 ak7375 snd_soc_wcd9335
>> regmap_slimbus snd_soc_wcd_classh apr snd_soc_apq8096
>> snd_soc_qcom_common snd_soc_core qcom_camss msm v4l2_fwnode 
>> snd_compress
>> ath10k_pci v4l2_async ath10k_core snd_pcm nxp_nci_i2c drm_exec nxp_nci
>> venus_core videobuf2_dma_sg snd_timer ath v4l2_mem2mem 
>> videobuf2_memops
>> mac80211 drm_dp_aux_bus snd gpu_sched nci videobuf2_v4l2 libarc4
>> soundcore videodev nfc slim_qcom_ngd_ctrl drm_display_helper hci_uart
>> pdr_interface videobuf2_common btqca drm_kms_helper slimbus 
>> i2c_qcom_cci
>> bluetooth mc qcom_q6v5_pas qcom_q6v5_mss qcom_pil_info qcom_q6v5
>> qcom_sysmon qcom_common qmi_helpers mdt_loader socinfo rmtfs_mem
>> pwm_ir_tx cfg80211 rfkill zram zsmalloc atmel_mxt_ts drm
>> drm_panel_orientation_quirks dm_mod ip_tables
>> [   92.989981] CPU: 2 PID: 1365 Comm: pool-megapixels Not tainted
>> 6.9.0-rc3+ #10
>> [   92.990003] Hardware name: Xiaomi Mi Note 2 (DT)
>> [   92.990020] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS
>> BTYPE=--)
>> [   92.990042] pc : device_link_put_kref+0xc/0xb8
>> [   92.990071] lr : device_link_del+0x30/0x48
>> [   92.990089] sp : ffff80008a5db9d0
>> [   92.990105] x29: ffff80008a5db9d0 x28: 0000000000000001 x27:
>> 0000000000000000
>> [   92.990143] x26: 0000000000000000 x25: ffff0000e79d9100 x24:
>> ffff0000e79d9500
>> [   92.990180] x23: ffff0000943f8568 x22: 00000000ffffffff x21:
>> 0000000000000000
>> [   92.990217] x20: 0000000000000000 x19: ffff800081352498 x18:
>> 0000000000000000
>> [   92.990253] x17: 0000000000000000 x16: 0000000000000000 x15:
>> 0000000000000168
>> [   92.990288] x14: 0000000000000000 x13: 0000000000000191 x12:
>> ffff800081259d58
>> [   92.990324] x11: 0000000000000001 x10: 0000000000000a60 x9 :
>> ffff80008a5db7e0
>> [   92.990359] x8 : ffff0000e79d9bc0 x7 : 0000000000000004 x6 :
>> 0000000000000190
>> [   92.990396] x5 : 0000000000000057 x4 : 0000000000000000 x3 :
>> 0000000000000000
>> [   92.990430] x2 : ffff0000e79d9100 x1 : 0000000000000000 x0 :
>> 0000000000000000
>> [   92.990466] Call trace:
>> [   92.990482]  device_link_put_kref+0xc/0xb8
>> [   92.990503]  device_link_del+0x30/0x48
>> [   92.990522]  vfe_pm_domain_off+0x24/0x38 [qcom_camss]
> 
> vfe_pm_domain_off() shall not be called before vfe_pm_domain_on() call.
> 
> If vfe_pm_domain_on() is called and returns failure, then a media 
> pipeline
> shall not be started, and vfe_pm_domain_off() shall not be called.
> 
> If vfe_pm_domain_on() is called and returns success, then 
> vfe->genpd_link
> is not NULL.
It can be null if the pm_domain_off is called twice somehow or it is 
called
before pm_domain_on.
This is the original function, it sets genpd_link to NULL:

void vfe_pm_domain_off(struct vfe_device *vfe)
{
         if (!vfe->genpd)
                 return;

         device_link_del(vfe->genpd_link);
         vfe->genpd_link = NULL;
}
Other possible case:
genpd_link can be NULL when pm_domain_on is failing or
when genpd is NULL

By the way pm_domain_on checks if genpd_link is NULL:
         vfe->genpd_link = device_link_add(camss->dev, vfe->genpd,
                                           DL_FLAG_STATELESS |
                                           DL_FLAG_PM_RUNTIME |
                                           DL_FLAG_RPM_ACTIVE);
         if (!vfe->genpd_link)
                 return -EINVAL;
It is not calling pm_domain_off on fail:

ret = vfe->res->hw_ops->pm_domain_on(vfe);
                 if (ret < 0)
                         goto error_pm_domain;

[...]

error_domain_off:
         vfe->res->hw_ops->pm_domain_off(vfe);

error_pm_domain:
         mutex_unlock(&vfe->power_lock);


camss_pm_domain_off also calls vfe_pm_domain_off what is used in 
camss-ispif
void camss_pm_domain_off(struct camss *camss, int id)
{
         if (id < camss->res->vfe_num) {
                 struct vfe_device *vfe = &camss->vfe[id];

                 vfe->res->hw_ops->pm_domain_off(vfe);
         }
}
> 
> Are there any perceptable flaws within the given above reasoning?
The camss will be broken and system also can recover correctly (only 
force reboot works.).
> 
> Since you've encountered a bug and taking the reasoning from above as
> correct, I believe the bug is present somewhere else, and if so, it 
> will
> remain unfixed by this change.
> 
>> [   92.990566]  vfe_put+0x9c/0xd0 [qcom_camss]
>> [   92.990601]  vfe_set_power+0x48/0x58 [qcom_camss]
>> [   92.990636]  pipeline_pm_power_one+0x154/0x158 [videodev]
>> [   92.990683]  pipeline_pm_power+0x74/0xfc [videodev]
>> [   92.990720]  v4l2_pipeline_pm_use+0x54/0x90 [videodev]
>> [   92.990757]  v4l2_pipeline_pm_put+0x14/0x34 [videodev]
>> [   92.990793]  video_release+0x2c/0x44 [qcom_camss]
>> [   92.990828]  v4l2_release+0xe4/0xec [videodev]
> 
> Please include the backtrace up to this point into the commit message.
> 
> --
> Best wishes,
> Vladimir

Re: [PATCH] media: qcom: camss: fix VFE pm domain off

[Vladimir Zapolskiy]

On 11/28/24 16:24, barnabas.czeman@mainlining.org wrote:
> On 2024-11-28 14:22, Vladimir Zapolskiy wrote:
>> On 11/28/24 12:27, barnabas.czeman@mainlining.org wrote:
>>> On 2024-11-28 10:10, Vladimir Zapolskiy wrote:
>>>> On 11/27/24 12:01, Yassine Oudjana wrote:
>>>>> On 22/11/2024 5:06 am, Barnabás Czémán wrote:
>>>>>> Fix NULL pointer check before device_link_del
>>>>>> is called.
>>>>
>>>> The intention is clear, but the context of the change is completely
>>>> lost.
>>>>
>>>>>> Fixes: eb73facec2c2 ("media: qcom: camss: Use common VFE
>>>>>> pm_domain_on/pm_domain_off where applicable")
>>>>
>>>> It's invalid, the change is not a fix.
>>> I don't agree this patch is fixing NULL pointer dereference.
>>>
>>> [   92.989120] Unable to handle kernel NULL pointer dereference at
>>> virtual address 000000000000032c
>>> [   92.989170] Mem abort info:
>>> [   92.989186]   ESR = 0x0000000096000004
>>> [   92.989203]   EC = 0x25: DABT (current EL), IL = 32 bits
>>> [   92.989221]   SET = 0, FnV = 0
>>> [   92.989237]   EA = 0, S1PTW = 0
>>> [   92.989253]   FSC = 0x04: level 0 translation fault
>>> [   92.989270] Data abort info:
>>> [   92.989284]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
>>> [   92.989300]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
>>> [   92.989317]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
>>> [   92.989335] user pgtable: 4k pages, 48-bit VAs,
>>> pgdp=00000001218a8000
>>> [   92.989354] [000000000000032c] pgd=0000000000000000,
>>> p4d=0000000000000000
>>> [   92.989389] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
>>> [   92.989408] Modules linked in: q6afe_dai q6asm_dai q6routing q6adm
>>> q6asm q6afe snd_q6dsp_common panel_lgphilips_sw43101 q6core venus_enc
>>> venus_dec videobuf2_dma_contig imx318 ak7375 snd_soc_wcd9335
>>> regmap_slimbus snd_soc_wcd_classh apr snd_soc_apq8096
>>> snd_soc_qcom_common snd_soc_core qcom_camss msm v4l2_fwnode
>>> snd_compress
>>> ath10k_pci v4l2_async ath10k_core snd_pcm nxp_nci_i2c drm_exec nxp_nci
>>> venus_core videobuf2_dma_sg snd_timer ath v4l2_mem2mem
>>> videobuf2_memops
>>> mac80211 drm_dp_aux_bus snd gpu_sched nci videobuf2_v4l2 libarc4
>>> soundcore videodev nfc slim_qcom_ngd_ctrl drm_display_helper hci_uart
>>> pdr_interface videobuf2_common btqca drm_kms_helper slimbus
>>> i2c_qcom_cci
>>> bluetooth mc qcom_q6v5_pas qcom_q6v5_mss qcom_pil_info qcom_q6v5
>>> qcom_sysmon qcom_common qmi_helpers mdt_loader socinfo rmtfs_mem
>>> pwm_ir_tx cfg80211 rfkill zram zsmalloc atmel_mxt_ts drm
>>> drm_panel_orientation_quirks dm_mod ip_tables
>>> [   92.989981] CPU: 2 PID: 1365 Comm: pool-megapixels Not tainted
>>> 6.9.0-rc3+ #10
>>> [   92.990003] Hardware name: Xiaomi Mi Note 2 (DT)
>>> [   92.990020] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS
>>> BTYPE=--)
>>> [   92.990042] pc : device_link_put_kref+0xc/0xb8
>>> [   92.990071] lr : device_link_del+0x30/0x48
>>> [   92.990089] sp : ffff80008a5db9d0
>>> [   92.990105] x29: ffff80008a5db9d0 x28: 0000000000000001 x27:
>>> 0000000000000000
>>> [   92.990143] x26: 0000000000000000 x25: ffff0000e79d9100 x24:
>>> ffff0000e79d9500
>>> [   92.990180] x23: ffff0000943f8568 x22: 00000000ffffffff x21:
>>> 0000000000000000
>>> [   92.990217] x20: 0000000000000000 x19: ffff800081352498 x18:
>>> 0000000000000000
>>> [   92.990253] x17: 0000000000000000 x16: 0000000000000000 x15:
>>> 0000000000000168
>>> [   92.990288] x14: 0000000000000000 x13: 0000000000000191 x12:
>>> ffff800081259d58
>>> [   92.990324] x11: 0000000000000001 x10: 0000000000000a60 x9 :
>>> ffff80008a5db7e0
>>> [   92.990359] x8 : ffff0000e79d9bc0 x7 : 0000000000000004 x6 :
>>> 0000000000000190
>>> [   92.990396] x5 : 0000000000000057 x4 : 0000000000000000 x3 :
>>> 0000000000000000
>>> [   92.990430] x2 : ffff0000e79d9100 x1 : 0000000000000000 x0 :
>>> 0000000000000000
>>> [   92.990466] Call trace:
>>> [   92.990482]  device_link_put_kref+0xc/0xb8
>>> [   92.990503]  device_link_del+0x30/0x48
>>> [   92.990522]  vfe_pm_domain_off+0x24/0x38 [qcom_camss]
>>
>> vfe_pm_domain_off() shall not be called before vfe_pm_domain_on() call.
>>
>> If vfe_pm_domain_on() is called and returns failure, then a media
>> pipeline
>> shall not be started, and vfe_pm_domain_off() shall not be called.
>>
>> If vfe_pm_domain_on() is called and returns success, then
>> vfe->genpd_link
>> is not NULL.
> It can be null if the pm_domain_off is called twice somehow or it is
> called
> before pm_domain_on.

Then this is the problem and this not yet identified problem shall be fixed.

The currently proposed change does not fix it, but hides more efficiently.

> This is the original function, it sets genpd_link to NULL:
> 
> void vfe_pm_domain_off(struct vfe_device *vfe)
> {
>           if (!vfe->genpd)
>                   return;
> 
>           device_link_del(vfe->genpd_link);
>           vfe->genpd_link = NULL;
> }
> Other possible case:
> genpd_link can be NULL when pm_domain_on is failing or
> when genpd is NULL



> By the way pm_domain_on checks if genpd_link is NULL:
>           vfe->genpd_link = device_link_add(camss->dev, vfe->genpd,
>                                             DL_FLAG_STATELESS |
>                                             DL_FLAG_PM_RUNTIME |
>                                             DL_FLAG_RPM_ACTIVE);
>           if (!vfe->genpd_link)
>                   return -EINVAL;
> It is not calling pm_domain_off on fail:
> 
> ret = vfe->res->hw_ops->pm_domain_on(vfe);
>                   if (ret < 0)
>                           goto error_pm_domain;
> 
> [...]
> 
> error_domain_off:
>           vfe->res->hw_ops->pm_domain_off(vfe);
> 
> error_pm_domain:
>           mutex_unlock(&vfe->power_lock);
> 
> 
> camss_pm_domain_off also calls vfe_pm_domain_off what is used in
> camss-ispif
> void camss_pm_domain_off(struct camss *camss, int id)
> {
>           if (id < camss->res->vfe_num) {
>                   struct vfe_device *vfe = &camss->vfe[id];
> 
>                   vfe->res->hw_ops->pm_domain_off(vfe);
>           }
> }
>>
>> Are there any perceptable flaws within the given above reasoning?
> The camss will be broken and system also can recover correctly (only
> force reboot works.).

Well, my question was about the reasoning, why there is another
problem.

I'm worried that the real bug will not be fixed by this change, and
I believe additional analysis is needed here.

>>
>> Since you've encountered a bug and taking the reasoning from above as
>> correct, I believe the bug is present somewhere else, and if so, it
>> will
>> remain unfixed by this change.
>>
>>> [   92.990566]  vfe_put+0x9c/0xd0 [qcom_camss]
>>> [   92.990601]  vfe_set_power+0x48/0x58 [qcom_camss]
>>> [   92.990636]  pipeline_pm_power_one+0x154/0x158 [videodev]
>>> [   92.990683]  pipeline_pm_power+0x74/0xfc [videodev]
>>> [   92.990720]  v4l2_pipeline_pm_use+0x54/0x90 [videodev]
>>> [   92.990757]  v4l2_pipeline_pm_put+0x14/0x34 [videodev]
>>> [   92.990793]  video_release+0x2c/0x44 [qcom_camss]
>>> [   92.990828]  v4l2_release+0xe4/0xec [videodev]
>>
>> Please include the backtrace up to this point into the commit message.
>>

--
Best wishes,
Vladimir