| Message ID | 20200917164721.2038541-1-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/doc: Document that modifiers are always required for fb | expand |
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> On Thu, Sep 17, 2020 at 6:48 PM Daniel Vetter <daniel.vetter@ffwll.ch> wrote: > > Even for legacy userspace, since otherwise GETFB2 is broken and if you > switch between modifier-less and modifier-aware compositors, smooth > transitions break. > > Also it's just best practice to make sure modifiers are invariant for > a given drm_fb, and that a modifier-aware kms drivers only has one > place to store them, ignoring any old implicit bo flags or whatever > else might float around. > > Motivated by some irc discussion with Bas about amdgpu modifier > support. > > Acked-by: Simon Ser <contact@emersion.fr> > Acked-by: Daniel Stone <daniels@collabora.com> > Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com> > Fixes: 455e00f1412f ("drm: Add getfb2 ioctl") > Cc: Daniel Stone <daniels@collabora.com> > Cc: Juston Li <juston.li@intel.com> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > Cc: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> > Cc: Marek Olšák <maraeo@gmail.com> > Cc: "Wentland, Harry" <harry.wentland@amd.com> > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> > --- > Sending this out again to double-check there's no objections or concerns. > From what I understand looking at the code the latest modifier patches for > amdgpu follow this now. > > Cheers, Daniel > --- > include/drm/drm_mode_config.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h > index a18f73eb3cf6..5ffbb4ed5b35 100644 > --- a/include/drm/drm_mode_config.h > +++ b/include/drm/drm_mode_config.h > @@ -58,6 +58,12 @@ struct drm_mode_config_funcs { > * actual modifier used if the request doesn't have it specified, > * ie. when (@mode_cmd->flags & DRM_MODE_FB_MODIFIERS) == 0. > * > + * IMPORTANT: These implied modifiers for legacy userspace must be > + * stored in struct &drm_framebuffer, including all relevant metadata > + * like &drm_framebuffer.pitches and &drm_framebuffer.offsets if the > + * modifier enables additional planes beyond the fourcc pixel format > + * code. This is required by the GETFB2 ioctl. > + * > * If the parameters are deemed valid and the backing storage objects in > * the underlying memory manager all exist, then the driver allocates > * a new &drm_framebuffer structure, subclassed to contain > @@ -915,6 +921,13 @@ struct drm_mode_config { > * @allow_fb_modifiers: > * > * Whether the driver supports fb modifiers in the ADDFB2.1 ioctl call. > + * > + * IMPORTANT: > + * > + * If this is set the driver must fill out the full implicit modifier > + * information in their &drm_mode_config_funcs.fb_create hook for legacy > + * userspace which does not set modifiers. Otherwise the GETFB2 ioctl is > + * broken for modifier aware userspace. > */ > bool allow_fb_modifiers; > > -- > 2.28.0 >
On Thu, Sep 17, 2020 at 07:24:58PM +0200, Bas Nieuwenhuizen wrote: > Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> > > On Thu, Sep 17, 2020 at 6:48 PM Daniel Vetter <daniel.vetter@ffwll.ch> wrote: > > > > Even for legacy userspace, since otherwise GETFB2 is broken and if you > > switch between modifier-less and modifier-aware compositors, smooth > > transitions break. > > > > Also it's just best practice to make sure modifiers are invariant for > > a given drm_fb, and that a modifier-aware kms drivers only has one > > place to store them, ignoring any old implicit bo flags or whatever > > else might float around. > > > > Motivated by some irc discussion with Bas about amdgpu modifier > > support. > > > > Acked-by: Simon Ser <contact@emersion.fr> > > Acked-by: Daniel Stone <daniels@collabora.com> > > Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com> > > Fixes: 455e00f1412f ("drm: Add getfb2 ioctl") > > Cc: Daniel Stone <daniels@collabora.com> > > Cc: Juston Li <juston.li@intel.com> > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > > Cc: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> > > Cc: Marek Olšák <maraeo@gmail.com> > > Cc: "Wentland, Harry" <harry.wentland@amd.com> > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Pushed to drm-misc-next, thanks for all the feedback. -Daniel > > --- > > Sending this out again to double-check there's no objections or concerns. > > From what I understand looking at the code the latest modifier patches for > > amdgpu follow this now. > > > > Cheers, Daniel > > --- > > include/drm/drm_mode_config.h | 13 +++++++++++++ > > 1 file changed, 13 insertions(+) > > > > diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h > > index a18f73eb3cf6..5ffbb4ed5b35 100644 > > --- a/include/drm/drm_mode_config.h > > +++ b/include/drm/drm_mode_config.h > > @@ -58,6 +58,12 @@ struct drm_mode_config_funcs { > > * actual modifier used if the request doesn't have it specified, > > * ie. when (@mode_cmd->flags & DRM_MODE_FB_MODIFIERS) == 0. > > * > > + * IMPORTANT: These implied modifiers for legacy userspace must be > > + * stored in struct &drm_framebuffer, including all relevant metadata > > + * like &drm_framebuffer.pitches and &drm_framebuffer.offsets if the > > + * modifier enables additional planes beyond the fourcc pixel format > > + * code. This is required by the GETFB2 ioctl. > > + * > > * If the parameters are deemed valid and the backing storage objects in > > * the underlying memory manager all exist, then the driver allocates > > * a new &drm_framebuffer structure, subclassed to contain > > @@ -915,6 +921,13 @@ struct drm_mode_config { > > * @allow_fb_modifiers: > > * > > * Whether the driver supports fb modifiers in the ADDFB2.1 ioctl call. > > + * > > + * IMPORTANT: > > + * > > + * If this is set the driver must fill out the full implicit modifier > > + * information in their &drm_mode_config_funcs.fb_create hook for legacy > > + * userspace which does not set modifiers. Otherwise the GETFB2 ioctl is > > + * broken for modifier aware userspace. > > */ > > bool allow_fb_modifiers; > > > > -- > > 2.28.0 > >
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h index a18f73eb3cf6..5ffbb4ed5b35 100644 --- a/include/drm/drm_mode_config.h +++ b/include/drm/drm_mode_config.h @@ -58,6 +58,12 @@ struct drm_mode_config_funcs { * actual modifier used if the request doesn't have it specified, * ie. when (@mode_cmd->flags & DRM_MODE_FB_MODIFIERS) == 0. * + * IMPORTANT: These implied modifiers for legacy userspace must be + * stored in struct &drm_framebuffer, including all relevant metadata + * like &drm_framebuffer.pitches and &drm_framebuffer.offsets if the + * modifier enables additional planes beyond the fourcc pixel format + * code. This is required by the GETFB2 ioctl. + * * If the parameters are deemed valid and the backing storage objects in * the underlying memory manager all exist, then the driver allocates * a new &drm_framebuffer structure, subclassed to contain @@ -915,6 +921,13 @@ struct drm_mode_config { * @allow_fb_modifiers: * * Whether the driver supports fb modifiers in the ADDFB2.1 ioctl call. + * + * IMPORTANT: + * + * If this is set the driver must fill out the full implicit modifier + * information in their &drm_mode_config_funcs.fb_create hook for legacy + * userspace which does not set modifiers. Otherwise the GETFB2 ioctl is + * broken for modifier aware userspace. */ bool allow_fb_modifiers;