[PATCH 1/2] accel/ivpu: Fix deadlock in ivpu_ms_cleanup()

[Jacek Lawrynowicz]

Hi,

On 3/25/2025 9:50 PM, Lizhi Hou wrote:
> 
> On 3/25/25 04:43, Maciej Falkowski wrote:
>> From: Jacek Lawrynowicz <jacek.lawrynowicz at linux.intel.com>
>>
>> Fix deadlock in ivpu_ms_cleanup() by preventing runtime resume after
>> file_priv->ms_lock is acquired.
>>
>> During a failure in runtime resume, a cold boot is executed, which
>> calls ivpu_ms_cleanup_all(). This function calls ivpu_ms_cleanup()
>> that acquires file_priv->ms_lock and causes the deadlock.
>>
>> Fixes: cdfad4db7756 ("accel/ivpu: Add NPU profiling support")
>> Cc: <stable at vger.kernel.org> # v6.11+
>> Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz at linux.intel.com>
>> Signed-off-by: Maciej Falkowski <maciej.falkowski at linux.intel.com>
>> ---
>>   drivers/accel/ivpu/ivpu_ms.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/accel/ivpu/ivpu_ms.c b/drivers/accel/ivpu/ivpu_ms.c
>> index ffe7b10f8a76..eb485cf15ad6 100644
>> --- a/drivers/accel/ivpu/ivpu_ms.c
>> +++ b/drivers/accel/ivpu/ivpu_ms.c
>> @@ -4,6 +4,7 @@
>>    */
>>     #include <drm/drm_file.h>
>> +#include <linux/pm_runtime.h>
>>     #include "ivpu_drv.h"
>>   #include "ivpu_gem.h"
>> @@ -281,6 +282,9 @@ int ivpu_ms_get_info_ioctl(struct drm_device *dev, void *data, struct drm_file *
>>   void ivpu_ms_cleanup(struct ivpu_file_priv *file_priv)
>>   {
>>       struct ivpu_ms_instance *ms, *tmp;
>> +    struct ivpu_device *vdev = file_priv->vdev;
>> +
>> +    pm_runtime_get_sync(vdev->drm.dev);
> 
> Could get_sync() be failed here? Maybe it is better to add warning for failure?

Yes, this could fail but we already have detailed warnings in runtime resume callback (ivpu_pm_runtime_resume_cb()).
> 
>>         mutex_lock(&file_priv->ms_lock);
>>   @@ -293,6 +297,8 @@ void ivpu_ms_cleanup(struct ivpu_file_priv *file_priv)
>>           free_instance(file_priv, ms);
>>         mutex_unlock(&file_priv->ms_lock);
>> +
>> +    pm_runtime_put_autosuspend(vdev->drm.dev);
>>   }
>>     void ivpu_ms_cleanup_all(struct ivpu_device *vdev)

Regards,
Jacek