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[i-g-t] tests/i915/kms_big_fb: trigger async flip with a dummy flip

Message ID 20220628110409.768308-1-arun.r.murthy@intel.com (mailing list archive)
State New, archived
Headers show
Series [i-g-t] tests/i915/kms_big_fb: trigger async flip with a dummy flip | expand

Commit Message

Murthy, Arun R June 28, 2022, 11:04 a.m. UTC
In oder to trigger the async flip, a dummy flip is required after sync
flip so as to update the watermarks for async in KMD which happens as
part of this dummy flip. Thereafter async memory update will act as a
trigger register.
Capturing the CRC is done after the async flip as async flip at some
times can consume fairly a vblank period time.

Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
---
 tests/i915/kms_big_fb.c | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

Comments

Karthik B S July 5, 2022, 9:27 a.m. UTC | #1
On 6/28/2022 4:34 PM, Arun R Murthy wrote:
> In oder to trigger the async flip, a dummy flip is required after sync
> flip so as to update the watermarks for async in KMD which happens as
> part of this dummy flip. Thereafter async memory update will act as a
> trigger register.
> Capturing the CRC is done after the async flip as async flip at some
> times can consume fairly a vblank period time.
>
> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> ---
>   tests/i915/kms_big_fb.c | 29 +++++++++++++++++++----------
>   1 file changed, 19 insertions(+), 10 deletions(-)
>
> diff --git a/tests/i915/kms_big_fb.c b/tests/i915/kms_big_fb.c
> index d50fde45..6caf3c31 100644
> --- a/tests/i915/kms_big_fb.c
> +++ b/tests/i915/kms_big_fb.c
> @@ -465,7 +465,7 @@ static bool test_pipe(data_t *data)
>   static bool
>   max_hw_stride_async_flip_test(data_t *data)
>   {
> -	uint32_t ret, startframe;
> +	uint32_t ret, frame;
>   	const uint32_t w = data->output->config.default_mode.hdisplay,
>   		       h = data->output->config.default_mode.vdisplay;
>   	igt_plane_t *primary;
> @@ -519,7 +519,19 @@ max_hw_stride_async_flip_test(data_t *data)
>   					  DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
>   
>   		igt_wait_for_vblank(data->drm_fd, data->display.pipes[primary->pipe->pipe].crtc_offset);
> -		startframe = kmstest_get_vblank(data->drm_fd, data->pipe, 0) + 1;
> +		/*
> +		 * In older platforms (<= Gen10), async address update bit is double buffered.
> +		 * So flip timestamp can be verified only from the second flip.
> +		 * The first async flip just enables the async address update.
> +		 * In platforms greater than DISPLAY13 the first async flip will be discarded
> +		 * in order to change the watermark levels as per the optimization. Hence the
> +		 * subsequent async flips will actually do the asynchronous flips.
> +		 */
> +		ret = drmModePageFlip(data->drm_fd, data->output->config.crtc->crtc_id,
> +						      data->big_fb_flip[i].fb_id,
> +						      DRM_MODE_PAGE_FLIP_ASYNC, NULL);
> +		igt_wait_for_vblank(data->drm_fd, data->display.pipes[primary->pipe->pipe].crtc_offset);
> +		frame = kmstest_get_vblank(data->drm_fd, data->pipe, 0) + 1;

Hi,

Should this be added inside a gen check similar to kms_async_flips?

>   
>   		for (int j = 0; j < 2; j++) {
>   			do {
> @@ -528,23 +540,20 @@ max_hw_stride_async_flip_test(data_t *data)
>   						      DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>   			} while (ret == -EBUSY);
>   			igt_assert(ret == 0);
> +			igt_pipe_crc_get_for_frame(data->drm_fd, data->pipe_crc,
> +					   frame, &compare_crc);
>   
> +			frame = kmstest_get_vblank(data->drm_fd, data->pipe, 0) + 1;
>   			do {
>   				ret = drmModePageFlip(data->drm_fd, data->output->config.crtc->crtc_id,
>   						      data->big_fb.fb_id,
>   						      DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>   			} while (ret == -EBUSY);
>   			igt_assert(ret == 0);
> +			igt_pipe_crc_get_for_frame(data->drm_fd, data->pipe_crc,
> +					   frame, &async_crc);

We should be moving this IMHO. By waiting for vblank after each async 
flip to capture CRC, what is the intended result? Seems to be completely 
changing the existing test logic.

Also, seems like we are overwriting the CRC captured for j = 0, as 
comparison is done outside this loop. Is this done on purpose?

Thanks,
Karthik.B.S
>   		}
>   
> -		igt_pipe_crc_get_for_frame(data->drm_fd, data->pipe_crc,
> -					   startframe, &compare_crc);
> -		igt_pipe_crc_get_for_frame(data->drm_fd, data->pipe_crc,
> -					   startframe + 1, &async_crc);
> -
> -		igt_assert_f(kmstest_get_vblank(data->drm_fd, data->pipe, 0) -
> -			     startframe == 1, "lost frames\n");
> -
>   		igt_assert_f(igt_check_crc_equal(&compare_crc, &async_crc)^(i^1),
>   			     "CRC failure with async flip, crc %s match for checked round\n",
>   			     i?"should":"shouldn't");
Murthy, Arun R July 5, 2022, 9:38 a.m. UTC | #2
> On 6/28/2022 4:34 PM, Arun R Murthy wrote:
> > In oder to trigger the async flip, a dummy flip is required after sync
> > flip so as to update the watermarks for async in KMD which happens as
> > part of this dummy flip. Thereafter async memory update will act as a
> > trigger register.
> > Capturing the CRC is done after the async flip as async flip at some
> > times can consume fairly a vblank period time.
> >
> > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> > ---
> >   tests/i915/kms_big_fb.c | 29 +++++++++++++++++++----------
> >   1 file changed, 19 insertions(+), 10 deletions(-)
> >
> > diff --git a/tests/i915/kms_big_fb.c b/tests/i915/kms_big_fb.c index
> > d50fde45..6caf3c31 100644
> > --- a/tests/i915/kms_big_fb.c
> > +++ b/tests/i915/kms_big_fb.c
> > @@ -465,7 +465,7 @@ static bool test_pipe(data_t *data)
> >   static bool
> >   max_hw_stride_async_flip_test(data_t *data)
> >   {
> > -	uint32_t ret, startframe;
> > +	uint32_t ret, frame;
> >   	const uint32_t w = data->output->config.default_mode.hdisplay,
> >   		       h = data->output->config.default_mode.vdisplay;
> >   	igt_plane_t *primary;
> > @@ -519,7 +519,19 @@ max_hw_stride_async_flip_test(data_t *data)
> >
> DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
> >
> >   		igt_wait_for_vblank(data->drm_fd, data-
> >display.pipes[primary->pipe->pipe].crtc_offset);
> > -		startframe = kmstest_get_vblank(data->drm_fd, data->pipe,
> 0) + 1;
> > +		/*
> > +		 * In older platforms (<= Gen10), async address update bit is
> double buffered.
> > +		 * So flip timestamp can be verified only from the second flip.
> > +		 * The first async flip just enables the async address update.
> > +		 * In platforms greater than DISPLAY13 the first async flip will
> be discarded
> > +		 * in order to change the watermark levels as per the
> optimization. Hence the
> > +		 * subsequent async flips will actually do the asynchronous
> flips.
> > +		 */
> > +		ret = drmModePageFlip(data->drm_fd, data->output-
> >config.crtc->crtc_id,
> > +						      data->big_fb_flip[i].fb_id,
> > +
> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
> > +		igt_wait_for_vblank(data->drm_fd, data-
> >display.pipes[primary->pipe->pipe].crtc_offset);
> > +		frame = kmstest_get_vblank(data->drm_fd, data->pipe, 0) +
> 1;
> 
> Hi,
> 
> Should this be added inside a gen check similar to kms_async_flips?

Yes sorry missed it!

> 
> >
> >   		for (int j = 0; j < 2; j++) {
> >   			do {
> > @@ -528,23 +540,20 @@ max_hw_stride_async_flip_test(data_t *data)
> >
> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
> >   			} while (ret == -EBUSY);
> >   			igt_assert(ret == 0);
> > +			igt_pipe_crc_get_for_frame(data->drm_fd, data-
> >pipe_crc,
> > +					   frame, &compare_crc);
> >
> > +			frame = kmstest_get_vblank(data->drm_fd, data-
> >pipe, 0) + 1;
> >   			do {
> >   				ret = drmModePageFlip(data->drm_fd, data-
> >output->config.crtc->crtc_id,
> >   						      data->big_fb.fb_id,
> >
> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
> >   			} while (ret == -EBUSY);
> >   			igt_assert(ret == 0);
> > +			igt_pipe_crc_get_for_frame(data->drm_fd, data-
> >pipe_crc,
> > +					   frame, &async_crc);
> 
> We should be moving this IMHO. By waiting for vblank after each async flip
> to capture CRC, what is the intended result? Seems to be completely
> changing the existing test logic.

We are getting the vblank count and based on that getting the crc. Now we know for async flip at
certain times it can consume a time equivalent to a vblank period. So in those scenarios getting crc
based on the vblank goes for a toss. Hence capturing the vblank start time stamp at the beginning
of each flip.

> 
> Also, seems like we are overwriting the CRC captured for j = 0, as comparison
> is done outside this loop. Is this done on purpose?

Now with the changing the vblank start frame capture being added before the async flip, CRC can
be captured outside the loop as well, but makes no sense. To maintain this order moving the CRC
Capture also after each frame.

Thanks and Regards,
Arun R Murthy
--------------------
Karthik B S July 5, 2022, 9:49 a.m. UTC | #3
On 7/5/2022 3:08 PM, Murthy, Arun R wrote:
>> On 6/28/2022 4:34 PM, Arun R Murthy wrote:
>>> In oder to trigger the async flip, a dummy flip is required after sync
>>> flip so as to update the watermarks for async in KMD which happens as
>>> part of this dummy flip. Thereafter async memory update will act as a
>>> trigger register.
>>> Capturing the CRC is done after the async flip as async flip at some
>>> times can consume fairly a vblank period time.
>>>
>>> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
>>> ---
>>>    tests/i915/kms_big_fb.c | 29 +++++++++++++++++++----------
>>>    1 file changed, 19 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/tests/i915/kms_big_fb.c b/tests/i915/kms_big_fb.c index
>>> d50fde45..6caf3c31 100644
>>> --- a/tests/i915/kms_big_fb.c
>>> +++ b/tests/i915/kms_big_fb.c
>>> @@ -465,7 +465,7 @@ static bool test_pipe(data_t *data)
>>>    static bool
>>>    max_hw_stride_async_flip_test(data_t *data)
>>>    {
>>> -	uint32_t ret, startframe;
>>> +	uint32_t ret, frame;
>>>    	const uint32_t w = data->output->config.default_mode.hdisplay,
>>>    		       h = data->output->config.default_mode.vdisplay;
>>>    	igt_plane_t *primary;
>>> @@ -519,7 +519,19 @@ max_hw_stride_async_flip_test(data_t *data)
>>>
>> DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
>>>    		igt_wait_for_vblank(data->drm_fd, data-
>>> display.pipes[primary->pipe->pipe].crtc_offset);
>>> -		startframe = kmstest_get_vblank(data->drm_fd, data->pipe,
>> 0) + 1;
>>> +		/*
>>> +		 * In older platforms (<= Gen10), async address update bit is
>> double buffered.
>>> +		 * So flip timestamp can be verified only from the second flip.
>>> +		 * The first async flip just enables the async address update.
>>> +		 * In platforms greater than DISPLAY13 the first async flip will
>> be discarded
>>> +		 * in order to change the watermark levels as per the
>> optimization. Hence the
>>> +		 * subsequent async flips will actually do the asynchronous
>> flips.
>>> +		 */
>>> +		ret = drmModePageFlip(data->drm_fd, data->output-
>>> config.crtc->crtc_id,
>>> +						      data->big_fb_flip[i].fb_id,
>>> +
>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>>> +		igt_wait_for_vblank(data->drm_fd, data-
>>> display.pipes[primary->pipe->pipe].crtc_offset);
>>> +		frame = kmstest_get_vblank(data->drm_fd, data->pipe, 0) +
>> 1;
>>
>> Hi,
>>
>> Should this be added inside a gen check similar to kms_async_flips?
> Yes sorry missed it!
>
>>>    		for (int j = 0; j < 2; j++) {
>>>    			do {
>>> @@ -528,23 +540,20 @@ max_hw_stride_async_flip_test(data_t *data)
>>>
>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>>>    			} while (ret == -EBUSY);
>>>    			igt_assert(ret == 0);
>>> +			igt_pipe_crc_get_for_frame(data->drm_fd, data-
>>> pipe_crc,
>>> +					   frame, &compare_crc);
>>>
>>> +			frame = kmstest_get_vblank(data->drm_fd, data-
>>> pipe, 0) + 1;
>>>    			do {
>>>    				ret = drmModePageFlip(data->drm_fd, data-
>>> output->config.crtc->crtc_id,
>>>    						      data->big_fb.fb_id,
>>>
>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>>>    			} while (ret == -EBUSY);
>>>    			igt_assert(ret == 0);
>>> +			igt_pipe_crc_get_for_frame(data->drm_fd, data-
>>> pipe_crc,
>>> +					   frame, &async_crc);
>> We should be moving this IMHO. By waiting for vblank after each async flip
>> to capture CRC, what is the intended result? Seems to be completely
>> changing the existing test logic.
> We are getting the vblank count and based on that getting the crc. Now we know for async flip at
> certain times it can consume a time equivalent to a vblank period. So in those scenarios getting crc
> based on the vblank goes for a toss. Hence capturing the vblank start time stamp at the beginning
> of each flip.

Hi,

But what is the the reference CRC we're expecting? The original logic is 
designed to match on one iteration and mismatch on the next using a 
combination of fb's by using async flips. But with these changes that 
whole logic goes for a toss?

>
>> Also, seems like we are overwriting the CRC captured for j = 0, as comparison
>> is done outside this loop. Is this done on purpose?
> Now with the changing the vblank start frame capture being added before the async flip, CRC can
> be captured outside the loop as well, but makes no sense. To maintain this order moving the CRC
> Capture also after each frame.

The CRC comparison is still outside the loop, so no point capturing 
CRC's if we finally discard it anyway?

Thanks,
Karthik.B.S
> Thanks and Regards,
> Arun R Murthy
> --------------------
Murthy, Arun R July 5, 2022, 10:16 a.m. UTC | #4
> On 7/5/2022 3:08 PM, Murthy, Arun R wrote:
> >> On 6/28/2022 4:34 PM, Arun R Murthy wrote:
> >>> In oder to trigger the async flip, a dummy flip is required after
> >>> sync flip so as to update the watermarks for async in KMD which
> >>> happens as part of this dummy flip. Thereafter async memory update
> >>> will act as a trigger register.
> >>> Capturing the CRC is done after the async flip as async flip at some
> >>> times can consume fairly a vblank period time.
> >>>
> >>> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> >>> ---
> >>>    tests/i915/kms_big_fb.c | 29 +++++++++++++++++++----------
> >>>    1 file changed, 19 insertions(+), 10 deletions(-)
> >>>
> >>> diff --git a/tests/i915/kms_big_fb.c b/tests/i915/kms_big_fb.c index
> >>> d50fde45..6caf3c31 100644
> >>> --- a/tests/i915/kms_big_fb.c
> >>> +++ b/tests/i915/kms_big_fb.c
> >>> @@ -465,7 +465,7 @@ static bool test_pipe(data_t *data)
> >>>    static bool
> >>>    max_hw_stride_async_flip_test(data_t *data)
> >>>    {
> >>> -	uint32_t ret, startframe;
> >>> +	uint32_t ret, frame;
> >>>    	const uint32_t w = data->output->config.default_mode.hdisplay,
> >>>    		       h = data->output->config.default_mode.vdisplay;
> >>>    	igt_plane_t *primary;
> >>> @@ -519,7 +519,19 @@ max_hw_stride_async_flip_test(data_t *data)
> >>>
> >> DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
> >>>    		igt_wait_for_vblank(data->drm_fd, data-
> >>> display.pipes[primary->pipe->pipe].crtc_offset);
> >>> -		startframe = kmstest_get_vblank(data->drm_fd, data->pipe,
> >> 0) + 1;
> >>> +		/*
> >>> +		 * In older platforms (<= Gen10), async address update bit is
> >> double buffered.
> >>> +		 * So flip timestamp can be verified only from the second flip.
> >>> +		 * The first async flip just enables the async address update.
> >>> +		 * In platforms greater than DISPLAY13 the first async flip will
> >> be discarded
> >>> +		 * in order to change the watermark levels as per the
> >> optimization. Hence the
> >>> +		 * subsequent async flips will actually do the asynchronous
> >> flips.
> >>> +		 */
> >>> +		ret = drmModePageFlip(data->drm_fd, data->output-
> >>> config.crtc->crtc_id,
> >>> +						      data->big_fb_flip[i].fb_id,
> >>> +
> >> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
> >>> +		igt_wait_for_vblank(data->drm_fd, data-
> >>> display.pipes[primary->pipe->pipe].crtc_offset);
> >>> +		frame = kmstest_get_vblank(data->drm_fd, data->pipe, 0) +
> >> 1;
> >>
> >> Hi,
> >>
> >> Should this be added inside a gen check similar to kms_async_flips?
> > Yes sorry missed it!
> >
> >>>    		for (int j = 0; j < 2; j++) {
> >>>    			do {
> >>> @@ -528,23 +540,20 @@ max_hw_stride_async_flip_test(data_t *data)
> >>>
> >> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
> >>>    			} while (ret == -EBUSY);
> >>>    			igt_assert(ret == 0);
> >>> +			igt_pipe_crc_get_for_frame(data->drm_fd, data-
> >>> pipe_crc,
> >>> +					   frame, &compare_crc);
> >>>
> >>> +			frame = kmstest_get_vblank(data->drm_fd, data-
> >>> pipe, 0) + 1;
> >>>    			do {
> >>>    				ret = drmModePageFlip(data->drm_fd, data-
> >>> output->config.crtc->crtc_id,
> >>>    						      data->big_fb.fb_id,
> >>>
> >> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
> >>>    			} while (ret == -EBUSY);
> >>>    			igt_assert(ret == 0);
> >>> +			igt_pipe_crc_get_for_frame(data->drm_fd, data-
> >>> pipe_crc,
> >>> +					   frame, &async_crc);
> >> We should be moving this IMHO. By waiting for vblank after each async
> >> flip to capture CRC, what is the intended result? Seems to be
> >> completely changing the existing test logic.
> > We are getting the vblank count and based on that getting the crc. Now
> > we know for async flip at certain times it can consume a time
> > equivalent to a vblank period. So in those scenarios getting crc based
> > on the vblank goes for a toss. Hence capturing the vblank start time stamp
> at the beginning of each flip.
> 
> Hi,
> 
> But what is the the reference CRC we're expecting? The original logic is
> designed to match on one iteration and mismatch on the next using a
> combination of fb's by using async flips. But with these changes that whole
> logic goes for a toss?
> 
But I see this logic doesn’t work. We cannot rely on the CRC based on the vblank time frame for each flips. Since this is a async flip and at times the async flip can consume a vblank time period for flipping. So the CRC captured based on starteframe+1 logic is not right.

Thanks and Regards,
Arun R Murthy
--------------------
Juha-Pekka Heikkilä July 5, 2022, 10:22 a.m. UTC | #5
Hi,

On 5.7.2022 12.49, Karthik B S wrote:
> On 7/5/2022 3:08 PM, Murthy, Arun R wrote:
>>> On 6/28/2022 4:34 PM, Arun R Murthy wrote:
>>>> In oder to trigger the async flip, a dummy flip is required after sync
>>>> flip so as to update the watermarks for async in KMD which happens as
>>>> part of this dummy flip. Thereafter async memory update will act as a
>>>> trigger register.
>>>> Capturing the CRC is done after the async flip as async flip at some
>>>> times can consume fairly a vblank period time.
>>>>
>>>> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
>>>> ---
>>>>    tests/i915/kms_big_fb.c | 29 +++++++++++++++++++----------
>>>>    1 file changed, 19 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/tests/i915/kms_big_fb.c b/tests/i915/kms_big_fb.c index
>>>> d50fde45..6caf3c31 100644
>>>> --- a/tests/i915/kms_big_fb.c
>>>> +++ b/tests/i915/kms_big_fb.c
>>>> @@ -465,7 +465,7 @@ static bool test_pipe(data_t *data)
>>>>    static bool
>>>>    max_hw_stride_async_flip_test(data_t *data)
>>>>    {
>>>> -    uint32_t ret, startframe;
>>>> +    uint32_t ret, frame;
>>>>        const uint32_t w = data->output->config.default_mode.hdisplay,
>>>>                   h = data->output->config.default_mode.vdisplay;
>>>>        igt_plane_t *primary;
>>>> @@ -519,7 +519,19 @@ max_hw_stride_async_flip_test(data_t *data)
>>>>
>>> DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
>>>>            igt_wait_for_vblank(data->drm_fd, data-
>>>> display.pipes[primary->pipe->pipe].crtc_offset);
>>>> -        startframe = kmstest_get_vblank(data->drm_fd, data->pipe,
>>> 0) + 1;
>>>> +        /*
>>>> +         * In older platforms (<= Gen10), async address update bit is
>>> double buffered.
>>>> +         * So flip timestamp can be verified only from the second 
>>>> flip.
>>>> +         * The first async flip just enables the async address update.
>>>> +         * In platforms greater than DISPLAY13 the first async flip 
>>>> will
>>> be discarded
>>>> +         * in order to change the watermark levels as per the
>>> optimization. Hence the
>>>> +         * subsequent async flips will actually do the asynchronous
>>> flips.
>>>> +         */
>>>> +        ret = drmModePageFlip(data->drm_fd, data->output-
>>>> config.crtc->crtc_id,
>>>> +                              data->big_fb_flip[i].fb_id,
>>>> +
>>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>>>> +        igt_wait_for_vblank(data->drm_fd, data-
>>>> display.pipes[primary->pipe->pipe].crtc_offset);
>>>> +        frame = kmstest_get_vblank(data->drm_fd, data->pipe, 0) +
>>> 1;
>>>
>>> Hi,
>>>
>>> Should this be added inside a gen check similar to kms_async_flips?
>> Yes sorry missed it!
>>
>>>>            for (int j = 0; j < 2; j++) {
>>>>                do {
>>>> @@ -528,23 +540,20 @@ max_hw_stride_async_flip_test(data_t *data)
>>>>
>>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>>>>                } while (ret == -EBUSY);
>>>>                igt_assert(ret == 0);
>>>> +            igt_pipe_crc_get_for_frame(data->drm_fd, data-
>>>> pipe_crc,
>>>> +                       frame, &compare_crc);
>>>>
>>>> +            frame = kmstest_get_vblank(data->drm_fd, data-
>>>> pipe, 0) + 1;
>>>>                do {
>>>>                    ret = drmModePageFlip(data->drm_fd, data-
>>>> output->config.crtc->crtc_id,
>>>>                                  data->big_fb.fb_id,
>>>>
>>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>>>>                } while (ret == -EBUSY);
>>>>                igt_assert(ret == 0);
>>>> +            igt_pipe_crc_get_for_frame(data->drm_fd, data-
>>>> pipe_crc,
>>>> +                       frame, &async_crc);
>>> We should be moving this IMHO. By waiting for vblank after each async 
>>> flip
>>> to capture CRC, what is the intended result? Seems to be completely
>>> changing the existing test logic.
>> We are getting the vblank count and based on that getting the crc. Now 
>> we know for async flip at
>> certain times it can consume a time equivalent to a vblank period. So 
>> in those scenarios getting crc
>> based on the vblank goes for a toss. Hence capturing the vblank start 
>> time stamp at the beginning
>> of each flip.
> 
> Hi,
> 
> But what is the the reference CRC we're expecting? The original logic is 
> designed to match on one iteration and mismatch on the next using a 
> combination of fb's by using async flips. But with these changes that 
> whole logic goes for a toss?
> 
>>
>>> Also, seems like we are overwriting the CRC captured for j = 0, as 
>>> comparison
>>> is done outside this loop. Is this done on purpose?
>> Now with the changing the vblank start frame capture being added 
>> before the async flip, CRC can
>> be captured outside the loop as well, but makes no sense. To maintain 
>> this order moving the CRC
>> Capture also after each frame.
> 
> The CRC comparison is still outside the loop, so no point capturing 
> CRC's if we finally discard it anyway?
> 

I think generally the idea Arun is changing is correct but he's missed 
how the test work.

I see there's Ville's change on kernel side for display_ver >=13 first 
async_flip is unconditionally (intentionally) missed, this is at 
intel_plane_do_async_flip(..) so this test will need adjustment

What Arun seem to have missed is on test those nested loops how they 
work, that part probably should've originally been commented in code bit 
better.

On original code there's after loop for j two time 
igt_pipe_crc_get_for_frame(..), first will capture crc from duration of 
loop of j, second will *wait* and capture current crc while there's 
framebuffer "big_fb" on screen (wait is about 1,5 frames). Inside j 
loop, against i is async flipped with fb from "big_fb_flip[i]" where one 
one fb look exactly like "big_fb" and check with this crc doesn't change 
when flip with same content. Then another "big_fb_flip[i]" is green 
color and check crc will change.

Now when inside "j" loop Arun added igt_pipe_crc_get_for_frame(..) this 
test becomes completely different because async flipping no more is 
tested do perform back'n'forth flipping.

/Juha-Pekka
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Murthy, Arun R July 5, 2022, 10:28 a.m. UTC | #6
> On 5.7.2022 12.49, Karthik B S wrote:
> > On 7/5/2022 3:08 PM, Murthy, Arun R wrote:
> >>> On 6/28/2022 4:34 PM, Arun R Murthy wrote:
> >>>> In oder to trigger the async flip, a dummy flip is required after
> >>>> sync flip so as to update the watermarks for async in KMD which
> >>>> happens as part of this dummy flip. Thereafter async memory update
> >>>> will act as a trigger register.
> >>>> Capturing the CRC is done after the async flip as async flip at
> >>>> some times can consume fairly a vblank period time.
> >>>>
> >>>> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> >>>> ---
> >>>>    tests/i915/kms_big_fb.c | 29 +++++++++++++++++++----------
> >>>>    1 file changed, 19 insertions(+), 10 deletions(-)
> >>>>
> >>>> diff --git a/tests/i915/kms_big_fb.c b/tests/i915/kms_big_fb.c
> >>>> index
> >>>> d50fde45..6caf3c31 100644
> >>>> --- a/tests/i915/kms_big_fb.c
> >>>> +++ b/tests/i915/kms_big_fb.c
> >>>> @@ -465,7 +465,7 @@ static bool test_pipe(data_t *data)
> >>>>    static bool
> >>>>    max_hw_stride_async_flip_test(data_t *data)
> >>>>    {
> >>>> -    uint32_t ret, startframe;
> >>>> +    uint32_t ret, frame;
> >>>>        const uint32_t w =
> >>>> data->output->config.default_mode.hdisplay,
> >>>>                   h = data->output->config.default_mode.vdisplay;
> >>>>        igt_plane_t *primary;
> >>>> @@ -519,7 +519,19 @@ max_hw_stride_async_flip_test(data_t *data)
> >>>>
> >>> DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
> >>>>            igt_wait_for_vblank(data->drm_fd, data-
> >>>> display.pipes[primary->pipe->pipe].crtc_offset);
> >>>> -        startframe = kmstest_get_vblank(data->drm_fd, data->pipe,
> >>> 0) + 1;
> >>>> +        /*
> >>>> +         * In older platforms (<= Gen10), async address update bit
> >>>> +is
> >>> double buffered.
> >>>> +         * So flip timestamp can be verified only from the second
> >>>> flip.
> >>>> +         * The first async flip just enables the async address update.
> >>>> +         * In platforms greater than DISPLAY13 the first async
> >>>> +flip
> >>>> will
> >>> be discarded
> >>>> +         * in order to change the watermark levels as per the
> >>> optimization. Hence the
> >>>> +         * subsequent async flips will actually do the
> >>>> +asynchronous
> >>> flips.
> >>>> +         */
> >>>> +        ret = drmModePageFlip(data->drm_fd, data->output-
> >>>> config.crtc->crtc_id,
> >>>> +                              data->big_fb_flip[i].fb_id,
> >>>> +
> >>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
> >>>> +        igt_wait_for_vblank(data->drm_fd, data-
> >>>> display.pipes[primary->pipe->pipe].crtc_offset);
> >>>> +        frame = kmstest_get_vblank(data->drm_fd, data->pipe, 0) +
> >>> 1;
> >>>
> >>> Hi,
> >>>
> >>> Should this be added inside a gen check similar to kms_async_flips?
> >> Yes sorry missed it!
> >>
> >>>>            for (int j = 0; j < 2; j++) {
> >>>>                do {
> >>>> @@ -528,23 +540,20 @@ max_hw_stride_async_flip_test(data_t
> *data)
> >>>>
> >>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
> >>>>                } while (ret == -EBUSY);
> >>>>                igt_assert(ret == 0);
> >>>> +            igt_pipe_crc_get_for_frame(data->drm_fd, data-
> >>>> pipe_crc,
> >>>> +                       frame, &compare_crc);
> >>>>
> >>>> +            frame = kmstest_get_vblank(data->drm_fd, data-
> >>>> pipe, 0) + 1;
> >>>>                do {
> >>>>                    ret = drmModePageFlip(data->drm_fd, data-
> >>>> output->config.crtc->crtc_id,
> >>>>                                  data->big_fb.fb_id,
> >>>>
> >>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
> >>>>                } while (ret == -EBUSY);
> >>>>                igt_assert(ret == 0);
> >>>> +            igt_pipe_crc_get_for_frame(data->drm_fd, data-
> >>>> pipe_crc,
> >>>> +                       frame, &async_crc);
> >>> We should be moving this IMHO. By waiting for vblank after each
> >>> async flip to capture CRC, what is the intended result? Seems to be
> >>> completely changing the existing test logic.
> >> We are getting the vblank count and based on that getting the crc.
> >> Now we know for async flip at certain times it can consume a time
> >> equivalent to a vblank period. So in those scenarios getting crc
> >> based on the vblank goes for a toss. Hence capturing the vblank start
> >> time stamp at the beginning of each flip.
> >
> > Hi,
> >
> > But what is the the reference CRC we're expecting? The original logic
> > is designed to match on one iteration and mismatch on the next using a
> > combination of fb's by using async flips. But with these changes that
> > whole logic goes for a toss?
> >
> >>
> >>> Also, seems like we are overwriting the CRC captured for j = 0, as
> >>> comparison is done outside this loop. Is this done on purpose?
> >> Now with the changing the vblank start frame capture being added
> >> before the async flip, CRC can be captured outside the loop as well,
> >> but makes no sense. To maintain this order moving the CRC Capture
> >> also after each frame.
> >
> > The CRC comparison is still outside the loop, so no point capturing
> > CRC's if we finally discard it anyway?
> >
> 
> I think generally the idea Arun is changing is correct but he's missed how the
> test work.
> 
> I see there's Ville's change on kernel side for display_ver >=13 first async_flip
> is unconditionally (intentionally) missed, this is at
> intel_plane_do_async_flip(..) so this test will need adjustment
> 
> What Arun seem to have missed is on test those nested loops how they
> work, that part probably should've originally been commented in code bit
> better.
> 
> On original code there's after loop for j two time
> igt_pipe_crc_get_for_frame(..), first will capture crc from duration of loop of
> j, second will *wait* and capture current crc while there's framebuffer
> "big_fb" on screen (wait is about 1,5 frames). Inside j loop, against i is async
> flipped with fb from "big_fb_flip[i]" where one one fb look exactly like
> "big_fb" and check with this crc doesn't change when flip with same content.
> Then another "big_fb_flip[i]" is green color and check crc will change.
> 
> Now when inside "j" loop Arun added igt_pipe_crc_get_for_frame(..) this test
> becomes completely different because async flipping no more is tested do
> perform back'n'forth flipping.
> 

Thanks for your comments JP, atleast its clear that this fix is required. But as commented
I am not aware of the concept behind this test, It would be better if someone can take up this
fix and correct the CRC capture sequence as well.

Thanks and Regards,
Arun R Murthy
--------------------
Juha-Pekka Heikkila July 5, 2022, 10:58 a.m. UTC | #7
Hi,

On 5.7.2022 13.28, Murthy, Arun R wrote:
>> On 5.7.2022 12.49, Karthik B S wrote:
>>> On 7/5/2022 3:08 PM, Murthy, Arun R wrote:
>>>>> On 6/28/2022 4:34 PM, Arun R Murthy wrote:
>>>>>> In oder to trigger the async flip, a dummy flip is required after
>>>>>> sync flip so as to update the watermarks for async in KMD which
>>>>>> happens as part of this dummy flip. Thereafter async memory update
>>>>>> will act as a trigger register.
>>>>>> Capturing the CRC is done after the async flip as async flip at
>>>>>> some times can consume fairly a vblank period time.
>>>>>>
>>>>>> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
>>>>>> ---
>>>>>>     tests/i915/kms_big_fb.c | 29 +++++++++++++++++++----------
>>>>>>     1 file changed, 19 insertions(+), 10 deletions(-)
>>>>>>
>>>>>> diff --git a/tests/i915/kms_big_fb.c b/tests/i915/kms_big_fb.c
>>>>>> index
>>>>>> d50fde45..6caf3c31 100644
>>>>>> --- a/tests/i915/kms_big_fb.c
>>>>>> +++ b/tests/i915/kms_big_fb.c
>>>>>> @@ -465,7 +465,7 @@ static bool test_pipe(data_t *data)
>>>>>>     static bool
>>>>>>     max_hw_stride_async_flip_test(data_t *data)
>>>>>>     {
>>>>>> -    uint32_t ret, startframe;
>>>>>> +    uint32_t ret, frame;
>>>>>>         const uint32_t w =
>>>>>> data->output->config.default_mode.hdisplay,
>>>>>>                    h = data->output->config.default_mode.vdisplay;
>>>>>>         igt_plane_t *primary;
>>>>>> @@ -519,7 +519,19 @@ max_hw_stride_async_flip_test(data_t *data)
>>>>>>
>>>>> DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
>>>>>>             igt_wait_for_vblank(data->drm_fd, data-
>>>>>> display.pipes[primary->pipe->pipe].crtc_offset);
>>>>>> -        startframe = kmstest_get_vblank(data->drm_fd, data->pipe,
>>>>> 0) + 1;
>>>>>> +        /*
>>>>>> +         * In older platforms (<= Gen10), async address update bit
>>>>>> +is
>>>>> double buffered.
>>>>>> +         * So flip timestamp can be verified only from the second
>>>>>> flip.
>>>>>> +         * The first async flip just enables the async address update.
>>>>>> +         * In platforms greater than DISPLAY13 the first async
>>>>>> +flip
>>>>>> will
>>>>> be discarded
>>>>>> +         * in order to change the watermark levels as per the
>>>>> optimization. Hence the
>>>>>> +         * subsequent async flips will actually do the
>>>>>> +asynchronous
>>>>> flips.
>>>>>> +         */
>>>>>> +        ret = drmModePageFlip(data->drm_fd, data->output-
>>>>>> config.crtc->crtc_id,
>>>>>> +                              data->big_fb_flip[i].fb_id,
>>>>>> +
>>>>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>>>>>> +        igt_wait_for_vblank(data->drm_fd, data-
>>>>>> display.pipes[primary->pipe->pipe].crtc_offset);
>>>>>> +        frame = kmstest_get_vblank(data->drm_fd, data->pipe, 0) +
>>>>> 1;
>>>>>
>>>>> Hi,
>>>>>
>>>>> Should this be added inside a gen check similar to kms_async_flips?
>>>> Yes sorry missed it!
>>>>
>>>>>>             for (int j = 0; j < 2; j++) {
>>>>>>                 do {
>>>>>> @@ -528,23 +540,20 @@ max_hw_stride_async_flip_test(data_t
>> *data)
>>>>>>
>>>>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>>>>>>                 } while (ret == -EBUSY);
>>>>>>                 igt_assert(ret == 0);
>>>>>> +            igt_pipe_crc_get_for_frame(data->drm_fd, data-
>>>>>> pipe_crc,
>>>>>> +                       frame, &compare_crc);
>>>>>>
>>>>>> +            frame = kmstest_get_vblank(data->drm_fd, data-
>>>>>> pipe, 0) + 1;
>>>>>>                 do {
>>>>>>                     ret = drmModePageFlip(data->drm_fd, data-
>>>>>> output->config.crtc->crtc_id,
>>>>>>                                   data->big_fb.fb_id,
>>>>>>
>>>>> DRM_MODE_PAGE_FLIP_ASYNC, NULL);
>>>>>>                 } while (ret == -EBUSY);
>>>>>>                 igt_assert(ret == 0);
>>>>>> +            igt_pipe_crc_get_for_frame(data->drm_fd, data-
>>>>>> pipe_crc,
>>>>>> +                       frame, &async_crc);
>>>>> We should be moving this IMHO. By waiting for vblank after each
>>>>> async flip to capture CRC, what is the intended result? Seems to be
>>>>> completely changing the existing test logic.
>>>> We are getting the vblank count and based on that getting the crc.
>>>> Now we know for async flip at certain times it can consume a time
>>>> equivalent to a vblank period. So in those scenarios getting crc
>>>> based on the vblank goes for a toss. Hence capturing the vblank start
>>>> time stamp at the beginning of each flip.
>>>
>>> Hi,
>>>
>>> But what is the the reference CRC we're expecting? The original logic
>>> is designed to match on one iteration and mismatch on the next using a
>>> combination of fb's by using async flips. But with these changes that
>>> whole logic goes for a toss?
>>>
>>>>
>>>>> Also, seems like we are overwriting the CRC captured for j = 0, as
>>>>> comparison is done outside this loop. Is this done on purpose?
>>>> Now with the changing the vblank start frame capture being added
>>>> before the async flip, CRC can be captured outside the loop as well,
>>>> but makes no sense. To maintain this order moving the CRC Capture
>>>> also after each frame.
>>>
>>> The CRC comparison is still outside the loop, so no point capturing
>>> CRC's if we finally discard it anyway?
>>>
>>
>> I think generally the idea Arun is changing is correct but he's missed how the
>> test work.
>>
>> I see there's Ville's change on kernel side for display_ver >=13 first async_flip
>> is unconditionally (intentionally) missed, this is at
>> intel_plane_do_async_flip(..) so this test will need adjustment
>>
>> What Arun seem to have missed is on test those nested loops how they
>> work, that part probably should've originally been commented in code bit
>> better.
>>
>> On original code there's after loop for j two time
>> igt_pipe_crc_get_for_frame(..), first will capture crc from duration of loop of
>> j, second will *wait* and capture current crc while there's framebuffer
>> "big_fb" on screen (wait is about 1,5 frames). Inside j loop, against i is async
>> flipped with fb from "big_fb_flip[i]" where one one fb look exactly like
>> "big_fb" and check with this crc doesn't change when flip with same content.
>> Then another "big_fb_flip[i]" is green color and check crc will change.
>>
>> Now when inside "j" loop Arun added igt_pipe_crc_get_for_frame(..) this test
>> becomes completely different because async flipping no more is tested do
>> perform back'n'forth flipping.
>>
> 
> Thanks for your comments JP, atleast its clear that this fix is required. But as commented
> I am not aware of the concept behind this test, It would be better if someone can take up this
> fix and correct the CRC capture sequence as well.

I think you are on the right track, just those inner loops are now 
mishandled.

I suspect you'd get effect you are after with something like below 
diff(totally untested). What the essential change is I added into that 
inner loop one extra async flip to "big_fb" in the beginning with hope 
that'll take care of display_ver>=13 .. but this change will invalidate 
"startframe" on display_ver>=13 so instead of get crc for chosen frames, 
drain crcs away before test and then get single crc two times. With this 
change probably that assert for "lost frames" will need to be adjusted 
too or just throw away. ..and you may need to add one extra 
igt_pipe_crc_get_single(..) before those two which will get the actual 
test crcs.

/Juha-Pekka


diff --git a/tests/i915/kms_big_fb.c b/tests/i915/kms_big_fb.c
index d50fde45..edcceaf1 100644
--- a/tests/i915/kms_big_fb.c
+++ b/tests/i915/kms_big_fb.c
@@ -518,10 +518,17 @@ max_hw_stride_async_flip_test(data_t *data)
                 igt_display_commit_atomic(&data->display,
 
DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);

+               igt_pipe_crc_drain(data->pipe_crc);
                 igt_wait_for_vblank(data->drm_fd, 
data->display.pipes[primary->pipe->pipe].crtc_offset);
                 startframe = kmstest_get_vblank(data->drm_fd, 
data->pipe, 0) + 1;

                 for (int j = 0; j < 2; j++) {
+                       do {
+                               ret = drmModePageFlip(data->drm_fd, 
data->output->config.crtc->crtc_id,
+                                                     data->big_fb.fb_id,
+ 
DRM_MODE_PAGE_FLIP_ASYNC, NULL);
+                       } while (ret == -EBUSY);
+
                         do {
                                 ret = drmModePageFlip(data->drm_fd, 
data->output->config.crtc->crtc_id,
 
data->big_fb_flip[i].fb_id,
@@ -537,10 +544,8 @@ max_hw_stride_async_flip_test(data_t *data)
                         igt_assert(ret == 0);
                 }

-               igt_pipe_crc_get_for_frame(data->drm_fd, data->pipe_crc,
-                                          startframe, &compare_crc);
-               igt_pipe_crc_get_for_frame(data->drm_fd, data->pipe_crc,
-                                          startframe + 1, &async_crc);
+               igt_pipe_crc_get_single(data->pipe_crc, &compare_crc);
+               igt_pipe_crc_get_single(data->pipe_crc, &async_crc);

                 igt_assert_f(kmstest_get_vblank(data->drm_fd, 
data->pipe, 0) -
                              startframe == 1, "lost frames\n");
diff mbox series

Patch

diff --git a/tests/i915/kms_big_fb.c b/tests/i915/kms_big_fb.c
index d50fde45..6caf3c31 100644
--- a/tests/i915/kms_big_fb.c
+++ b/tests/i915/kms_big_fb.c
@@ -465,7 +465,7 @@  static bool test_pipe(data_t *data)
 static bool
 max_hw_stride_async_flip_test(data_t *data)
 {
-	uint32_t ret, startframe;
+	uint32_t ret, frame;
 	const uint32_t w = data->output->config.default_mode.hdisplay,
 		       h = data->output->config.default_mode.vdisplay;
 	igt_plane_t *primary;
@@ -519,7 +519,19 @@  max_hw_stride_async_flip_test(data_t *data)
 					  DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
 
 		igt_wait_for_vblank(data->drm_fd, data->display.pipes[primary->pipe->pipe].crtc_offset);
-		startframe = kmstest_get_vblank(data->drm_fd, data->pipe, 0) + 1;
+		/*
+		 * In older platforms (<= Gen10), async address update bit is double buffered.
+		 * So flip timestamp can be verified only from the second flip.
+		 * The first async flip just enables the async address update.
+		 * In platforms greater than DISPLAY13 the first async flip will be discarded
+		 * in order to change the watermark levels as per the optimization. Hence the
+		 * subsequent async flips will actually do the asynchronous flips.
+		 */
+		ret = drmModePageFlip(data->drm_fd, data->output->config.crtc->crtc_id,
+						      data->big_fb_flip[i].fb_id,
+						      DRM_MODE_PAGE_FLIP_ASYNC, NULL);
+		igt_wait_for_vblank(data->drm_fd, data->display.pipes[primary->pipe->pipe].crtc_offset);
+		frame = kmstest_get_vblank(data->drm_fd, data->pipe, 0) + 1;
 
 		for (int j = 0; j < 2; j++) {
 			do {
@@ -528,23 +540,20 @@  max_hw_stride_async_flip_test(data_t *data)
 						      DRM_MODE_PAGE_FLIP_ASYNC, NULL);
 			} while (ret == -EBUSY);
 			igt_assert(ret == 0);
+			igt_pipe_crc_get_for_frame(data->drm_fd, data->pipe_crc,
+					   frame, &compare_crc);
 
+			frame = kmstest_get_vblank(data->drm_fd, data->pipe, 0) + 1;
 			do {
 				ret = drmModePageFlip(data->drm_fd, data->output->config.crtc->crtc_id,
 						      data->big_fb.fb_id,
 						      DRM_MODE_PAGE_FLIP_ASYNC, NULL);
 			} while (ret == -EBUSY);
 			igt_assert(ret == 0);
+			igt_pipe_crc_get_for_frame(data->drm_fd, data->pipe_crc,
+					   frame, &async_crc);
 		}
 
-		igt_pipe_crc_get_for_frame(data->drm_fd, data->pipe_crc,
-					   startframe, &compare_crc);
-		igt_pipe_crc_get_for_frame(data->drm_fd, data->pipe_crc,
-					   startframe + 1, &async_crc);
-
-		igt_assert_f(kmstest_get_vblank(data->drm_fd, data->pipe, 0) -
-			     startframe == 1, "lost frames\n");
-
 		igt_assert_f(igt_check_crc_equal(&compare_crc, &async_crc)^(i^1),
 			     "CRC failure with async flip, crc %s match for checked round\n",
 			     i?"should":"shouldn't");