Re: [PATCH] accel/ivpu: Improve IVPU_TEST_MODE_FW_TEST handling

[Andrzej Kacprowski <andrzej.kacprowski@linux.intel.com>]

On 07-Oct-26 12:38 PM, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] accel/ivpu: IRQ disable depth leak in FW_TEST mode due to unbalanced disable_irq()
> --
> 
> commit 03c00af9f26af13756e29777951597b1aedc577d
> Author: Andrzej Kacprowski <andrzej.kacprowski@linux.intel.com>
> 
> accel/ivpu: Improve IVPU_TEST_MODE_FW_TEST handling
> 
> When driver is operating in IVPU_TEST_MODE_FW_TEST debug mode
> it should boot the firmware, but skip communication with
> the firmware. There is no need to enable interrupts or send messages.
> The output of the firmware test will be available in the
> firmware log.
> 
>> diff --git a/drivers/accel/ivpu/ivpu_drv.c b/drivers/accel/ivpu/ivpu_drv.c
>> index 647684219e9d3..d66abf645e7b9 100644
>> --- a/drivers/accel/ivpu/ivpu_drv.c
>> +++ b/drivers/accel/ivpu/ivpu_drv.c
> 
> [ ... ]
> 
>> @@ -487,6 +484,9 @@ int ivpu_boot(struct ivpu_device *vdev)
>>   		return ret;
>>   	}
>>   
>> +	if (ivpu_test_mode & IVPU_TEST_MODE_FW_TEST)
>> +		return 0;
>> +
> 
> [Severity: High]
> Does this early return cause an IRQ disable depth leak?
> 
> Since ivpu_boot() skips the call to enable_irq() when IVPU_TEST_MODE_FW_TEST
> is enabled, it breaks the enable/disable symmetry.
> 
> Later, during teardown paths like ivpu_prepare_for_reset(), disable_irq()
> is called unconditionally:
> 
> drivers/accel/ivpu/ivpu_drv.c:ivpu_prepare_for_reset() {
>      ...
>      disable_irq(vdev->irq);
>      ...
> }
> 
> Calling disable_irq() without a matching enable_irq() increments the disable
> depth on each suspend/resume cycle. If the user dynamically disables FW_TEST
> mode via sysfs, subsequent enable_irq() calls will only decrement the
> accumulated depth by 1, leaving the physical interrupt permanently disabled.
> 
>>   	ret = ivpu_wait_for_ready(vdev);
>>   	if (ret) {
>>   		ivpu_err(vdev, "Failed to boot the firmware: %d\n", ret);
> 
Will be addressed in v2 patch.