2021-03-27 11:25:15

by Simon Ser

[permalink] [raw]
Subject: Re: [PATCH] drm: DON'T require each CRTC to have a unique primary plane

On Saturday, March 27th, 2021 at 12:22 PM, Paul Cercueil <[email protected]> wrote:

> The ingenic-drm driver has two mutually exclusive primary planes
> already; so the fact that a CRTC must have one and only one primary
> plane is an invalid assumption.

Why does this driver expose two primary planes, if it only has a single
CRTC?


2021-03-27 11:27:53

by Paul Cercueil

[permalink] [raw]
Subject: Re: [PATCH] drm: DON'T require each CRTC to have a unique primary plane

It has two mutually exclusive background planes (same Z level) + one
overlay plane.

-Paul


Le sam. 27 mars 2021 ? 11:24, Simon Ser <[email protected]> a ?crit
:
> On Saturday, March 27th, 2021 at 12:22 PM, Paul Cercueil
> <[email protected]> wrote:
>
>> The ingenic-drm driver has two mutually exclusive primary planes
>> already; so the fact that a CRTC must have one and only one primary
>> plane is an invalid assumption.
>
> Why does this driver expose two primary planes, if it only has a
> single
> CRTC?


2021-03-29 08:25:17

by Pekka Paalanen

[permalink] [raw]
Subject: Re: [PATCH] drm: DON'T require each CRTC to have a unique primary plane

On Sat, 27 Mar 2021 11:26:26 +0000
Paul Cercueil <[email protected]> wrote:

> It has two mutually exclusive background planes (same Z level) + one
> overlay plane.

What's the difference between the two background planes?

How will generic userspace know to pick the "right" one?


Thanks,
pq

> Le sam. 27 mars 2021 à 11:24, Simon Ser <[email protected]> a écrit
> :
> > On Saturday, March 27th, 2021 at 12:22 PM, Paul Cercueil
> > <[email protected]> wrote:
> >
> >> The ingenic-drm driver has two mutually exclusive primary planes
> >> already; so the fact that a CRTC must have one and only one primary
> >> plane is an invalid assumption.
> >
> > Why does this driver expose two primary planes, if it only has a
> > single
> > CRTC?
>
>
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel


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2021-03-29 11:44:54

by Paul Cercueil

[permalink] [raw]
Subject: Re: [PATCH] drm: DON'T require each CRTC to have a unique primary plane

Hi,

Le lun. 29 mars 2021 ? 11:15, Pekka Paalanen <[email protected]> a
?crit :
> On Sat, 27 Mar 2021 11:26:26 +0000
> Paul Cercueil <[email protected]> wrote:
>
>> It has two mutually exclusive background planes (same Z level) + one
>> overlay plane.
>
> What's the difference between the two background planes?
>
> How will generic userspace know to pick the "right" one?

First primary plane cannot scale, supports RGB and C8. Second primary
plane goes through the IPU, and as such can scale and convert pixel
formats; it supports RGB, non-planar YUV, and multi-planar YUV.

Right now the userspace apps we have will simply pick the first one
that fits the bill.

Cheers,
-Paul

>> Le sam. 27 mars 2021 ? 11:24, Simon Ser <[email protected]> a
>> ?crit
>> :
>> > On Saturday, March 27th, 2021 at 12:22 PM, Paul Cercueil
>> > <[email protected]> wrote:
>> >
>> >> The ingenic-drm driver has two mutually exclusive primary planes
>> >> already; so the fact that a CRTC must have one and only one
>> primary
>> >> plane is an invalid assumption.
>> >
>> > Why does this driver expose two primary planes, if it only has a
>> > single
>> > CRTC?
>>
>>
>> _______________________________________________
>> dri-devel mailing list
>> [email protected]
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>


2021-03-29 14:38:09

by Pekka Paalanen

[permalink] [raw]
Subject: Re: [PATCH] drm: DON'T require each CRTC to have a unique primary plane

On Mon, 29 Mar 2021 12:41:00 +0100
Paul Cercueil <[email protected]> wrote:

> Hi,
>
> Le lun. 29 mars 2021 à 11:15, Pekka Paalanen <[email protected]> a
> écrit :
> > On Sat, 27 Mar 2021 11:26:26 +0000
> > Paul Cercueil <[email protected]> wrote:
> >
> >> It has two mutually exclusive background planes (same Z level) + one
> >> overlay plane.
> >
> > What's the difference between the two background planes?
> >
> > How will generic userspace know to pick the "right" one?
>
> First primary plane cannot scale, supports RGB and C8. Second primary
> plane goes through the IPU, and as such can scale and convert pixel
> formats; it supports RGB, non-planar YUV, and multi-planar YUV.
>
> Right now the userspace apps we have will simply pick the first one
> that fits the bill.

What would be the downside of exposing just one "virtual" primary
plane, and then have the driver pick one of the two hardware planes as
appropriate per modeset?


Thanks,
pq

> >> Le sam. 27 mars 2021 à 11:24, Simon Ser <[email protected]> a
> >> écrit
> >> :
> >> > On Saturday, March 27th, 2021 at 12:22 PM, Paul Cercueil
> >> > <[email protected]> wrote:
> >> >
> >> >> The ingenic-drm driver has two mutually exclusive primary planes
> >> >> already; so the fact that a CRTC must have one and only one
> >> primary
> >> >> plane is an invalid assumption.
> >> >
> >> > Why does this driver expose two primary planes, if it only has a
> >> > single
> >> > CRTC?
> >>
> >>
> >> _______________________________________________
> >> dri-devel mailing list
> >> [email protected]
> >> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> >
>
>


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2021-03-29 15:23:48

by Paul Cercueil

[permalink] [raw]
Subject: Re: [PATCH] drm: DON'T require each CRTC to have a unique primary plane



Le lun. 29 mars 2021 ? 17:35, Pekka Paalanen <[email protected]> a
?crit :
> On Mon, 29 Mar 2021 12:41:00 +0100
> Paul Cercueil <[email protected]> wrote:
>
>> Hi,
>>
>> Le lun. 29 mars 2021 ? 11:15, Pekka Paalanen <[email protected]>
>> a
>> ?crit :
>> > On Sat, 27 Mar 2021 11:26:26 +0000
>> > Paul Cercueil <[email protected]> wrote:
>> >
>> >> It has two mutually exclusive background planes (same Z level)
>> + one
>> >> overlay plane.
>> >
>> > What's the difference between the two background planes?
>> >
>> > How will generic userspace know to pick the "right" one?
>>
>> First primary plane cannot scale, supports RGB and C8. Second
>> primary
>> plane goes through the IPU, and as such can scale and convert pixel
>> formats; it supports RGB, non-planar YUV, and multi-planar YUV.
>>
>> Right now the userspace apps we have will simply pick the first one
>> that fits the bill.
>
> What would be the downside of exposing just one "virtual" primary
> plane, and then have the driver pick one of the two hardware planes as
> appropriate per modeset?

The IPU plane is in a different driver, so all the callbacks are
different. That sounds like it would be a mess.

-Paul

> Thanks,
> pq
>
>> >> Le sam. 27 mars 2021 ? 11:24, Simon Ser <[email protected]> a
>> >> ?crit
>> >> :
>> >> > On Saturday, March 27th, 2021 at 12:22 PM, Paul Cercueil
>> >> > <[email protected]> wrote:
>> >> >
>> >> >> The ingenic-drm driver has two mutually exclusive primary
>> planes
>> >> >> already; so the fact that a CRTC must have one and only one
>> >> primary
>> >> >> plane is an invalid assumption.
>> >> >
>> >> > Why does this driver expose two primary planes, if it only
>> has a
>> >> > single
>> >> > CRTC?
>> >>
>> >>
>> >> _______________________________________________
>> >> dri-devel mailing list
>> >> [email protected]
>> >> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>> >
>>
>>
>