[v2,6/6] drm/i915: Do not do fb src adjustments for NV12

Op 17-04-18 om 10:09 schreef Srinivas, Vidya:
>
>> -----Original Message-----
>> From: Srinivas, Vidya
>> Sent: Tuesday, April 17, 2018 1:32 PM
>> To: 'Maarten Lankhorst' <maarten.lankhorst@linux.intel.com>; Saarinen,
>> Jani <jani.saarinen@intel.com>; intel-gfx@lists.freedesktop.org
>> Cc: Kamath, Sunil <sunil.kamath@intel.com>
>> Subject: RE: [PATCH v2 6/6] drm/i915: Do not do fb src adjustments for
>> NV12
>>
>>
>>
>>> -----Original Message-----
>>> From: Maarten Lankhorst [mailto:maarten.lankhorst@linux.intel.com]
>>> Sent: Tuesday, April 17, 2018 1:21 PM
>>> To: Srinivas, Vidya <vidya.srinivas@intel.com>; Saarinen, Jani
>>> <jani.saarinen@intel.com>; intel-gfx@lists.freedesktop.org
>>> Cc: Kamath, Sunil <sunil.kamath@intel.com>
>>> Subject: Re: [PATCH v2 6/6] drm/i915: Do not do fb src adjustments for
>>> NV12
>>>
>>> Op 17-04-18 om 09:38 schreef Srinivas, Vidya:
>>>>> -----Original Message-----
>>>>> From: Maarten Lankhorst [mailto:maarten.lankhorst@linux.intel.com]
>>>>> Sent: Tuesday, April 17, 2018 12:55 PM
>>>>> To: Saarinen, Jani <jani.saarinen@intel.com>; Srinivas, Vidya
>>>>> <vidya.srinivas@intel.com>; intel-gfx-trybot@lists.freedesktop.org;
>>>>> intel- gfx@lists.freedesktop.org
>>>>> Cc: Kamath, Sunil <sunil.kamath@intel.com>
>>>>> Subject: Re: [PATCH v2 6/6] drm/i915: Do not do fb src adjustments
>>>>> for
>>>>> NV12
>>>>>
>>>>> Op 17-04-18 om 08:03 schreef Saarinen, Jani:
>>>>>> Lets move this to intel-gfx to get more eyes on it.
>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: Srinivas, Vidya
>>>>>>> Sent: tiistai 17. huhtikuuta 2018 5.47
>>>>>>> To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>;
>>>>>>> intel-gfx- trybot@lists.freedesktop.org
>>>>>>> Cc: Kamath, Sunil <sunil.kamath@intel.com>; Saarinen, Jani
>>>>>>> <jani.saarinen@intel.com>
>>>>>>> Subject: RE: [PATCH v2 6/6] drm/i915: Do not do fb src
>>>>>>> adjustments for NV12
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Maarten Lankhorst
>>>>>>>> [mailto:maarten.lankhorst@linux.intel.com]
>>>>>>>> Sent: Monday, April 16, 2018 8:00 PM
>>>>>>>> To: Srinivas, Vidya <vidya.srinivas@intel.com>; intel-gfx-
>>>>>>>> trybot@lists.freedesktop.org
>>>>>>>> Cc: Kamath, Sunil <sunil.kamath@intel.com>; Saarinen, Jani
>>>>>>>> <jani.saarinen@intel.com>
>>>>>>>> Subject: Re: [PATCH v2 6/6] drm/i915: Do not do fb src
>>>>>>>> adjustments for
>>>>>>>> NV12
>>>>>>>>
>>>>>>>> Hmm, more thought about src adjustments...
>>>>>>>>
>>>>>>>> Op 13-04-18 om 07:22 schreef Vidya Srinivas:
>>>>>>>>> We skip src trunction/adjustments for
>>>>>>>>> NV12 case and handle the sizes directly.
>>>>>>>>> Without this, pipe fifo underruns are seen on APL/KBL.
>>>>>>>>>
>>>>>>>>> v2: For NV12, making the src coordinates multiplier of 4
>>>>>>>>>
>>>>>>>>> Credits-to: Maarten Lankhorst
>>>>>>>>> <maarten.lankhorst@linux.intel.com>
>>>>>>>>> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
>>>>>>>>> ---
>>>>>>>>>  drivers/gpu/drm/i915/intel_display.c | 11 +++++++++++
>>>>>>>>> drivers/gpu/drm/i915/intel_sprite.c  | 15 +++++++++++++++
>>>>>>>>>  2 files changed, 26 insertions(+)
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_display.c
>>>>>>>>> b/drivers/gpu/drm/i915/intel_display.c
>>>>>>>>> index bc83f10..f64708f 100644
>>>>>>>>> --- a/drivers/gpu/drm/i915/intel_display.c
>>>>>>>>> +++ b/drivers/gpu/drm/i915/intel_display.c
>>>>>>>>> @@ -12978,6 +12978,10 @@ intel_check_primary_plane(struct
>>>>>>>> intel_plane *plane,
>>>>>>>>>  	bool can_position = false;
>>>>>>>>>  	int ret;
>>>>>>>>>  	uint32_t pixel_format = 0;
>>>>>>>>> +	struct drm_plane_state *plane_state = &state->base;
>>>>>>>>> +	struct drm_rect *src = &plane_state->src;
>>>>>>>>> +
>>>>>>>>> +	*src = drm_plane_state_src(plane_state);
>>>>>>>>>
>>>>>>>>>  	if (INTEL_GEN(dev_priv) >= 9) {
>>>>>>>>>  		/* use scaler when colorkey is not required */ @@ -
>>> 13001,6
>>>>>>>>> +13005,13 @@ intel_check_primary_plane(struct intel_plane
>>> *plane,
>>>>>>>>>  	if (!state->base.fb)
>>>>>>>>>  		return 0;
>>>>>>>>>
>>>>>>>>> +	if (pixel_format == DRM_FORMAT_NV12) {
>>>>>>>>> +		src->x1 = (((src->x1 >> 16)/4)*4) << 16;
>>>>>>>>> +		src->x2 = (((src->x2 >> 16)/4)*4) << 16;
>>>>>>>>> +		src->y1 = (((src->y1 >> 16)/4)*4) << 16;
>>>>>>>>> +		src->y2 = (((src->y2 >> 16)/4)*4) << 16;
>>>>>>>>> +	}
>>>>>>>> Lets reject non multiple of 4 coordinates for plane_state's
>>>>>>>> src_x and src_y, and before adjustment also reject non multiple
>>>>>>>> of 4 src_w/src_h.fter that we can also reject clipping to the
>>>>>>>> right/bottom edge of the screen, if the pipe_src_w/h is not a
>>>>>>>> multiple of 4. That way an application trying to go beyond the
>> screen.
>>>>>>> kms_plane_scaling and some other tests during execution generate
>>>>>>> lots of non mult of 4 buffer width/height. All these tests will
>>>>>>> show fail in the IGT BAT.
>>>>>>> In some cases, even thought the width and height will be multiple
>>>>>>> of
>>>>>>> 4 before the Adjustment (say our 16x16 buffer), this after
>>>>>>> adjustment becomes a 15 in intel_check_sprite_plane.
>>>>>>> This again would cause underrun. If we reject non multiple of 4s
>>>>>>> in our skl_update_scaler also, then even simple tests with 16x16
>>>>>>> like rotation will fail due to it getting adjusted.
>>>>> Correct. This is why we fix up to a multiple of 4 after
>>>>> adjustments, and reject user passed coordinates before adjustment..
>>>>> plane_state->src_x/y/w/h is the property set by the user, while the
>>>>> plane_state->src rect is set and fixed up in the kernel.
>>>>>
>>>>> Rejecting clipping with positive coordinates if pipe_src w/h is not
>>>>> a multiple of 4 will fix a border case that shouldn't affect most
>>>>> modes, where the plane wouldn't extend to the crtc borders, which
>>>>> is
>>> what userspace wants there.
>>>> Thank you. Oh okay. Sorry. I thought we just reject and not do the
>>>> fixing
>>> (mult of 4 later).
>>>> Sure, I will change the patch to also reject the coordinates before
>>>> adjustment (if its not Mult of 4).
>>>>
>>>>
>>> This can be done in skl_check_plane_surface,
>>> plane_state->src_{x,y,w,h} contains the user requested values.
>> Apologies for asking again. The adjustments are done in check_plane (both
>> primary and sprite) And towards the end of check_plane we call the
>> skl_check_plane_surface.
>> I got your point that we will reject the user requested values if they are not
>> multiple of 4.
>> But before we reach skl_check_plane_surface, they would’ve been
>> adjusted/clipped etc They wont remain user requested as is when they enter
>> skl_check_plane_surface.
>> Please correct me if I am wrong or I am missing in understanding something
>> here :(
>>
>> I can add the add conversion to multiple of 4 in skl_check_plane_surface but
>> rejection should be done before the clipping/adjustment Or else, I move the
>> entire clipping/adjustment code to skl_check_plane_surface?
>>
> Sorry, I got it. You said, we don’t do adjustments in case of NV12 in sprite and move
> The handling to skl_check_plane_surface. I will do the change and submit. Sorry.
> Thank you.
>
Something like below? Untested..
We should probably also restrict NV12 fb creation to not allow CCS formats.

~Maarten

[v2,6/6] drm/i915: Do not do fb src adjustments for NV12

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