All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mark Yacoub <markyacoub@chromium.org>
To: Daniel Stone <daniel@fooishbar.org>
Cc: "Michel Dänzer" <michel@daenzer.net>,
	"amd-gfx list" <amd-gfx@lists.freedesktop.org>,
	"Maling list - DRI developers" <dri-devel@lists.freedesktop.org>,
	"Deucher, Alexander" <alexander.deucher@amd.com>,
	"Mark Yacoub" <markyacoub@google.com>
Subject: Re: [PATCH] drm/amdgpu: Ensure that the modifier requested is supported by plane.
Date: Wed, 24 Mar 2021 10:58:17 -0400	[thread overview]
Message-ID: <CAJUqKUqQ0yrxpr+QVRXYXMk1hBRNByD0TP6mM0oLY54jDZimbw@mail.gmail.com> (raw)
In-Reply-To: <CAPj87rP+WkUPbS3yyGGfy0SRm_hsnCCUav99Dg2Q+tXCiJ5D+A@mail.gmail.com>

On Wed, Mar 24, 2021 at 8:10 AM Daniel Stone <daniel@fooishbar.org> wrote:
>
> On Wed, 24 Mar 2021 at 10:53, Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> wrote:
>>
>> On Wed, Mar 24, 2021 at 11:13 AM Michel Dänzer <michel@daenzer.net> wrote:
>>>
>>> No modifier support does not imply linear. It's generally signalled via DRM_FORMAT_MOD_INVALID, which roughly means "tiling is determined by driver specific mechanisms".
So you mean it would make more sense to be more explicit in handling
DRM_FORMAT_MOD_INVALID as an incoming modifier (which will, just like
DRM_FORMAT_MOD_LINEAR, will return true in
dm_plane_format_mod_supported)?
>>
>>
>> Doesn't quite work that way in the kernel sadly. If you don't set DRM_MODE_FB_MODIFIERS then the modifier fields have to be 0 (which happens to alias DRM_FORMAT_MOD_LINEAR and then now deprecated DRM_FORMAT_MOD_NONE). This is verified in shared drm code.
>>
>> (and all userspace code I've seen simply doesn't set DRM_MODE_FB_MODIFIERS if the incoming modifier is DRM_FORMAT_MOD_INVALID)
>
>
> Yes, but even though the field is zero, the lack of the flag means it must be treated as INVALID. If the kernel is not doing this, the kernel is objectively wrong. (And I know it doesn't do this in most cases, because otherwise I wouldn't be able to use this GNOME session on an Intel laptop, where modifiers are blacklisted.)
>
> Cheers,
> Daniel
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

WARNING: multiple messages have this Message-ID (diff)
From: Mark Yacoub <markyacoub@chromium.org>
To: Daniel Stone <daniel@fooishbar.org>
Cc: "Michel Dänzer" <michel@daenzer.net>,
	"amd-gfx list" <amd-gfx@lists.freedesktop.org>,
	"Maling list - DRI developers" <dri-devel@lists.freedesktop.org>,
	"Bas Nieuwenhuizen" <bas@basnieuwenhuizen.nl>,
	"Deucher, Alexander" <alexander.deucher@amd.com>,
	"Mark Yacoub" <markyacoub@google.com>
Subject: Re: [PATCH] drm/amdgpu: Ensure that the modifier requested is supported by plane.
Date: Wed, 24 Mar 2021 10:58:17 -0400	[thread overview]
Message-ID: <CAJUqKUqQ0yrxpr+QVRXYXMk1hBRNByD0TP6mM0oLY54jDZimbw@mail.gmail.com> (raw)
In-Reply-To: <CAPj87rP+WkUPbS3yyGGfy0SRm_hsnCCUav99Dg2Q+tXCiJ5D+A@mail.gmail.com>

On Wed, Mar 24, 2021 at 8:10 AM Daniel Stone <daniel@fooishbar.org> wrote:
>
> On Wed, 24 Mar 2021 at 10:53, Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> wrote:
>>
>> On Wed, Mar 24, 2021 at 11:13 AM Michel Dänzer <michel@daenzer.net> wrote:
>>>
>>> No modifier support does not imply linear. It's generally signalled via DRM_FORMAT_MOD_INVALID, which roughly means "tiling is determined by driver specific mechanisms".
So you mean it would make more sense to be more explicit in handling
DRM_FORMAT_MOD_INVALID as an incoming modifier (which will, just like
DRM_FORMAT_MOD_LINEAR, will return true in
dm_plane_format_mod_supported)?
>>
>>
>> Doesn't quite work that way in the kernel sadly. If you don't set DRM_MODE_FB_MODIFIERS then the modifier fields have to be 0 (which happens to alias DRM_FORMAT_MOD_LINEAR and then now deprecated DRM_FORMAT_MOD_NONE). This is verified in shared drm code.
>>
>> (and all userspace code I've seen simply doesn't set DRM_MODE_FB_MODIFIERS if the incoming modifier is DRM_FORMAT_MOD_INVALID)
>
>
> Yes, but even though the field is zero, the lack of the flag means it must be treated as INVALID. If the kernel is not doing this, the kernel is objectively wrong. (And I know it doesn't do this in most cases, because otherwise I wouldn't be able to use this GNOME session on an Intel laptop, where modifiers are blacklisted.)
>
> Cheers,
> Daniel
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

  reply	other threads:[~2021-03-24 14:58 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-10 16:14 [PATCH] drm/amdgpu: Ensure that the modifier requested is supported by plane Mark Yacoub
2021-03-10 16:14 ` Mark Yacoub
2021-03-22 15:17 ` Mark Yacoub
2021-03-22 15:17   ` Mark Yacoub
2021-03-23 15:02 ` Alex Deucher
2021-03-23 15:02   ` Alex Deucher
2021-03-23 15:32   ` Mark Yacoub
2021-03-23 15:32     ` Mark Yacoub
2021-03-24 10:13     ` Michel Dänzer
2021-03-24 10:13       ` Michel Dänzer
2021-03-24 10:53       ` Bas Nieuwenhuizen
2021-03-24 10:53         ` Bas Nieuwenhuizen
2021-03-24 12:10         ` Daniel Stone
2021-03-24 12:10           ` Daniel Stone
2021-03-24 14:58           ` Mark Yacoub [this message]
2021-03-24 14:58             ` Mark Yacoub
2021-03-24 15:25             ` Daniel Stone
2021-03-24 15:25               ` Daniel Stone
2021-03-24 15:32               ` Mark Yacoub
2021-03-24 15:32                 ` Mark Yacoub
2021-03-23 15:08 ` Bas Nieuwenhuizen
2021-03-23 15:08   ` Bas Nieuwenhuizen
2021-03-23 15:34   ` Mark Yacoub
2021-03-23 15:34     ` Mark Yacoub

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAJUqKUqQ0yrxpr+QVRXYXMk1hBRNByD0TP6mM0oLY54jDZimbw@mail.gmail.com \
    --to=markyacoub@chromium.org \
    --cc=alexander.deucher@amd.com \
    --cc=amd-gfx@lists.freedesktop.org \
    --cc=daniel@fooishbar.org \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=markyacoub@google.com \
    --cc=michel@daenzer.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.