[PATCH] linux-dmabuf: send deprecated format events

[Philipp Zabel]

On Fri, 2017-12-15 at 10:51 +0000, Daniel Stone wrote:
> Hi Philipp,
> 
> On 15 December 2017 at 10:46, Philipp Zabel <p.zabel at pengutronix.de> wrote:
> > On Fri, 2017-12-15 at 09:46 +0000, Daniel Stone wrote:
> > > On 15 December 2017 at 09:25, Philipp Zabel <p.zabel at pengutronix.de> wrote:
> > > > Send format events instead of the modifier event, if the client binds on
> > > > a protocol version before version 3, skipping formats that only support
> > > > non-linear modifiers.
> > > 
> > > Thanks for this! Could I please persuade you to take on one additional
> > > change though?
> > > 
> > > Specifically, if has_dmabuf_import_modifiers is not supported,
> > > gl-renderer will return 0 for num_formats. In this case, it seems like
> > > we should send a conservative list: ARGB8888, XRGB8888, and maybe
> > > speculatively the YUV formats we have hardcoded conversions for
> > > (provided we have R8/RG8 support, cf. the patches from Arnaud).
> > 
> > Should we modify gl_renderer_query_dmabuf_formats to return that list of
> > hardcoded formats if has_dmabuf_import_modifiers is not supported?
> 
> That was exactly what I had in mind.
> 
> Cheers,
> Daniel
> _______________________________________________
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> wayland-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/wayland-devel

I haven't tested this yet with has_dmabuf_import_modifiers disabled, but
looking at this, I wonder whether this is the right thing to do.

If has_dmabuf_import_modifiers is set and the driver reports R8/RG88 in
query_dmabuf_formats, shouldn't we add the YUV formats as well?

----------8<----------
gl-renderer: return conservative format list if dmabuf import modifiers unsupported
  
If the EGL_EXT_image_dma_buf_import_modifiers extension is not
supported, let gl_renderer_query_dmabuf_formats return a hardcoded
fallback list. That list contains ARGB8888, XRGB8888, and if the
GL_EXT_texture_rg extension is supported, YUYV, NV12, YUV420, and
YUV444.
    
Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>

diff --git a/libweston/gl-renderer.c b/libweston/gl-renderer.c
index abf556f0..ee31a86d 100644
--- a/libweston/gl-renderer.c
+++ b/libweston/gl-renderer.c
@@ -2088,14 +2088,23 @@ gl_renderer_query_dmabuf_formats(struct weston_compositor *wc,
 				int **formats, int *num_formats)
 {
 	struct gl_renderer *gr = get_renderer(wc);
+	int fallback_formats[] = {
+		DRM_FORMAT_ARGB8888,
+		DRM_FORMAT_XRGB8888,
+		DRM_FORMAT_YUYV,
+		DRM_FORMAT_NV12,
+		DRM_FORMAT_YUV420,
+		DRM_FORMAT_YUV444,
+	};
+	bool fallback = false;
 	EGLint num;
 
 	assert(gr->has_dmabuf_import);
 
 	if (!gr->has_dmabuf_import_modifiers ||
 	    !gr->query_dmabuf_formats(gr->egl_display, 0, NULL, &num)) {
-		*num_formats = 0;
-		return;
+		num = gr->has_gl_texture_rg ? ARRAY_LENGTH(fallback_formats) : 2;
+		fallback = true;
 	}
 
 	*formats = calloc(num, sizeof(int));
@@ -2103,6 +2112,13 @@ gl_renderer_query_dmabuf_formats(struct weston_compositor *wc,
 		*num_formats = 0;
 		return;
 	}
+
+	if (fallback) {
+		memcpy(formats, fallback_formats, num * sizeof(int));
+		*num_formats = num;
+		return;
+	}
+
 	if (!gr->query_dmabuf_formats(gr->egl_display, num, *formats, &num)) {
 		*num_formats = 0;
 		free(*formats);
---------->8----------

regards
Philipp