Am 13.04.2018 um 09:01 schrieb S, Shirish:
>
>
> On 4/13/2018 11:53 AM, Christian König wrote:
>> Am 13.04.2018 um 06:07 schrieb Shirish S:
>>> amdgpu_ib_ring_tests() runs test IB's on rings at boot
>>> contributes to ~500 ms of amdgpu driver's boot time.
>>>
>>> This patch defers it and adds a check to report
>>> in amdgpu_info_ioctl() if it was scheduled or not.
>>
>> That is rather suboptimal, but see below.
>>
> Which part is sub-optimal, deferring or checking if the work is
> scheduled?
That was about the check. We should wait for the test to finish instead
of printing an error and continuing.
>>>
>>> Signed-off-by: Shirish S <shirish.s at amd.com>
>>> ---
>>>  drivers/gpu/drm/amd/amdgpu/amdgpu.h       | 2 ++
>>> Â drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 20 +++++++++++++++++---
>>>  drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c   | 3 +++
>>> Â 3 files changed, 22 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> index 5734871..ae8f722 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> @@ -1611,6 +1611,8 @@ struct amdgpu_device {
>>> Â Â Â Â Â Â /* delayed work_func for deferring clockgating during resume */
>>>      struct delayed_work    late_init_work;
>>> +Â Â Â /* delayed work_func to defer testing IB's on rings during boot */
>>> +   struct delayed_work    late_init_test_ib_work;
>>
>> You must put the IB test into the late_init_work as well, otherwise
>> the two delayed workers can race with each other.
>>
> I thought from the comment above the declaration, its clear why i am
> creating 2 work structures.
> late_init_work is to optimize resume time and late_init_test_ib_work
> is to optimize the boot time.
> There cant be race as the context in which they are called are totally
> different.
Late init enables power and clock gating. If I'm not completely mistaken
we don't do the power/clock gating earlier because we had to wait for
the IB test to finish.
Could be that modern ASICs have additional logic to prevent that, but
the last time I worked on this power gating a block while you run
something on it could even crash the whole system.
>>>       struct amdgpu_virt   virt;
>>> Â Â Â Â Â /* firmware VRAM reservation */
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> index 1762eb4..e65a5e6 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> @@ -63,6 +63,7 @@ MODULE_FIRMWARE("amdgpu/vega12_gpu_info.bin");
>>> Â MODULE_FIRMWARE("amdgpu/raven_gpu_info.bin");
>>> Â Â #define AMDGPU_RESUME_MSÂ Â Â Â Â Â Â 2000
>>> +#define AMDGPU_IB_TEST_SCHED_MSÂ Â Â Â Â Â Â 2000
>>> Â Â static const char *amdgpu_asic_name[] = {
>>> Â Â Â Â Â "TAHITI",
>>> @@ -2105,6 +2106,16 @@ bool amdgpu_device_asic_has_dc_support(enum
>>> amd_asic_type asic_type)
>>> Â Â Â Â Â }
>>> Â }
>>> Â +static void amdgpu_device_late_init_test_ib_func_handler(struct
>>> work_struct *work)
>>> +{
>>> +Â Â Â struct amdgpu_device *adev =
>>> +Â Â Â Â Â Â Â container_of(work, struct amdgpu_device,
>>> late_init_test_ib_work.work);
>>> +Â Â Â int r = amdgpu_ib_ring_tests(adev);
>>> +
>>> +Â Â Â if (r)
>>> +Â Â Â Â Â Â Â DRM_ERROR("ib ring test failed (%d).\n", r);
>>> +}
>>> +
>>> Â /**
>>> Â Â * amdgpu_device_has_dc_support - check if dc is supported
>>> Â Â *
>>> @@ -2212,6 +2223,8 @@ int amdgpu_device_init(struct amdgpu_device
>>> *adev,
>>> Â Â Â Â Â INIT_LIST_HEAD(&adev->ring_lru_list);
>>> Â Â Â Â Â spin_lock_init(&adev->ring_lru_list_lock);
>>> Â +Â Â Â INIT_DELAYED_WORK(&adev->late_init_test_ib_work,
>>> +Â Â Â Â Â Â Â Â Â Â Â Â Â amdgpu_device_late_init_test_ib_func_handler);
>>> Â Â Â Â Â INIT_DELAYED_WORK(&adev->late_init_work,
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â amdgpu_device_ip_late_init_func_handler);
>>> Â @@ -2374,9 +2387,9 @@ int amdgpu_device_init(struct amdgpu_device
>>> *adev,
>>> Â Â Â Â Â Â Â Â Â goto failed;
>>> Â Â Â Â Â }
>>> Â -Â Â Â r = amdgpu_ib_ring_tests(adev);
>>> -Â Â Â if (r)
>>> -Â Â Â Â Â Â Â DRM_ERROR("ib ring test failed (%d).\n", r);
>>> +Â Â Â /* Schedule amdgpu_ib_ring_tests() */
>>> +Â Â Â mod_delayed_work(system_wq, &adev->late_init_test_ib_work,
>>> +Â Â Â Â Â Â Â Â Â Â Â msecs_to_jiffies(AMDGPU_IB_TEST_SCHED_MS));
>>
>> That doesn't work like you intended. mod_delayed_work() overrides the
>> existing handler.
>>
>> What you wanted to use is queue_delayed_work(), but as I said we
>> should only have one delayed worker.
> mod_delayed_work() is safer and optimal method that replaces
> cancel_delayed_work() followed by queue_delayed_work().
> (https://lkml.org/lkml/2011/2/3/175)
> But if you strongly insist i don't mind changing it.
Well, mod_delayed_work() does NOT replace queue_delayed_work(). Those
two functions are for different use cases.
The link you posted actually explains it quite well:
> So, cancel_delayed_work() followed by queue_delayed_work() schedules
> the work to be executed at the specified time regardless of the
> current pending state while queue_delayed_work() takes effect iff
> currently the work item is not pending.
queue_delayed_work() takes only effect if the work item is not already
pending/executing.
In other words with queue_delayed_work() you don't risk executing things
twice when the work is already executing.
While with mod_delayed_work() you absolutely make sure to execute things
twice when it is already running.
If I'm not completely mistaken it should not matter in this case, but
queue_delayed_work() is used more commonly I think.
>>
>>> Â Â Â Â Â Â if (amdgpu_sriov_vf(adev))
>>> Â Â Â Â Â Â Â Â Â amdgpu_virt_init_data_exchange(adev);
>>> @@ -2469,6 +2482,7 @@ void amdgpu_device_fini(struct amdgpu_device
>>> *adev)
>>> Â Â Â Â Â }
>>> Â Â Â Â Â adev->accel_working = false;
>>> Â Â Â Â Â cancel_delayed_work_sync(&adev->late_init_work);
>>> + cancel_delayed_work_sync(&adev->late_init_test_ib_work);
>>> Â Â Â Â Â /* free i2c buses */
>>> Â Â Â Â Â if (!amdgpu_device_has_dc_support(adev))
>>> Â Â Â Â Â Â Â Â Â amdgpu_i2c_fini(adev);
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>> index 487d39e..057bd9a 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>> @@ -279,6 +279,9 @@ static int amdgpu_info_ioctl(struct drm_device
>>> *dev, void *data, struct drm_file
>>> Â Â Â Â Â if (!info->return_size || !info->return_pointer)
>>> Â Â Â Â Â Â Â Â Â return -EINVAL;
>>> Â +Â Â Â if (delayed_work_pending(&adev->late_init_test_ib_work))
>>> +Â Â Â Â Â Â Â DRM_ERROR("IB test on ring not executed\n");
>>> +
>>
>> Please use flush_delayed_work() instead of issuing and error here.
>>
> Agree, wasn't sure of what to do here :).
> So i will re-spin with the flush part added. Hope this reply clarifies
> your comments.
> Thanks.
> Regards,
> Shirish S
>> Regards,
>> Christian.
>>
>>> Â Â Â Â Â switch (info->query) {
>>> Â Â Â Â Â case AMDGPU_INFO_ACCEL_WORKING:
>>> Â Â Â Â Â Â Â Â Â ui32 = adev->accel_working;
>>
>
