panfrost: Don't flip scanout

The mesa/st flips the viewport, so we respect that rather than
trying to flip the framebuffer itself and ignoring the viewport and
using a messy heuristic.

However, this brings an underlying disagreement about the interpretation
of winding order to light. The blob uses a different strategy than Mesa
for handling viewport Y flipping, so the meanings of the winding order
bit are flipped for it. To keep things clean on our end, we rename to
explicitly use Gallium (rather than flipped OpenGL) conventions.

Fixes upside-down Xwayland/egl windows.

v2: Adjust lowering configuration to correctly flip gl_PointCoord.y and
gl_FragCoord.y. v1 was R-b'd by Tomeu, but then retracted due to these
regressions which are not fixed.

Suggested-by: Rob Clark <[email protected]>
Signed-off-by: Alyssa Rosenzweig <[email protected]>
Sort-of-reviewed-by: Tomeu Vizoso <[email protected]>

1 files changed, 4 insertions, 13 deletions

diff --git a/src/gallium/drivers/panfrost/pan_sfbd.c b/src/gallium/drivers/panfrost/pan_sfbd.c
index 4235c198199..6989cd925a8 100644
--- a/src/gallium/drivers/panfrost/pan_sfbd.c
+++ b/src/gallium/drivers/panfrost/pan_sfbd.c
@@ -87,8 +87,7 @@ panfrost_sfbd_clear(
 static void
 panfrost_sfbd_set_cbuf(
                 struct mali_single_framebuffer *fb,
-                struct pipe_surface *surf,
-                bool flip_y)
+                struct pipe_surface *surf)
 {
         struct panfrost_resource *rsrc = pan_resource(surf->texture);
 
@@ -97,15 +96,7 @@ panfrost_sfbd_set_cbuf(
         fb->format = panfrost_sfbd_format(surf);
 
         if (rsrc->bo->layout == PAN_LINEAR) {
-                mali_ptr framebuffer = rsrc->bo->gpu;
-
-                /* The default is upside down from OpenGL's perspective. */
-                if (flip_y) {
-                        framebuffer += stride * (surf->texture->height0 - 1);
-                        stride = -stride;
-                }
-
-                fb->framebuffer = framebuffer;
+                fb->framebuffer = rsrc->bo->gpu;
                 fb->stride = stride;
         } else {
                 fprintf(stderr, "Invalid render layout\n");
@@ -116,7 +107,7 @@ panfrost_sfbd_set_cbuf(
 /* Creates an SFBD for the FRAGMENT section of the bound framebuffer */
 
 mali_ptr
-panfrost_sfbd_fragment(struct panfrost_context *ctx, bool flip_y)
+panfrost_sfbd_fragment(struct panfrost_context *ctx)
 {
         struct panfrost_job *job = panfrost_get_job_for_fbo(ctx);
         struct mali_single_framebuffer fb = panfrost_emit_sfbd(ctx);
@@ -125,7 +116,7 @@ panfrost_sfbd_fragment(struct panfrost_context *ctx, bool flip_y)
 
         /* SFBD does not support MRT natively; sanity check */
         assert(ctx->pipe_framebuffer.nr_cbufs == 1);
-        panfrost_sfbd_set_cbuf(&fb, ctx->pipe_framebuffer.cbufs[0], flip_y);
+        panfrost_sfbd_set_cbuf(&fb, ctx->pipe_framebuffer.cbufs[0]);
 
         if (ctx->pipe_framebuffer.zsbuf) {
                 /* TODO */