radv: fix a GPU hang when MRTs are sparse

When the i-th target format is set, all previous target formats
must be non-zero to avoid hangs. In other words, without this
if a fragment shader exports mrt0, mrt2 and mrt3, the GPU hangs
because the target format of mrt1 is zero.

This fixes DXVK GPU hangs with "Seven: The Days Long Gone",
"GTA V" and probably more games.

Cc: "18.0" 18.1" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

diff --git a/src/amd/vulkan/radv_pipeline.c b/src/amd/vulkan/radv_pipeline.c
index 375f7c357d38cfb19ea6df1bc4d89829e099a6da..b8b425aca9f65415a271fd7e1c92c77e6b4960ae 100644 (file)
--- a/src/amd/vulkan/radv_pipeline.c
+++ b/src/amd/vulkan/radv_pipeline.c
@@ -504,6 +504,7 @@ radv_pipeline_compute_spi_color_formats(struct radv_pipeline *pipeline,
        RADV_FROM_HANDLE(radv_render_pass, pass, pCreateInfo->renderPass);
        struct radv_subpass *subpass = pass->subpasses + pCreateInfo->subpass;
        unsigned col_format = 0;
+       unsigned num_targets;
 
        for (unsigned i = 0; i < (blend->single_cb_enable ? 1 : subpass->color_count); ++i) {
                unsigned cf;
@@ -528,6 +529,15 @@ radv_pipeline_compute_spi_color_formats(struct radv_pipeline *pipeline,
        if (blend->mrt0_is_dual_src)
                col_format |= (col_format & 0xf) << 4;
        blend->spi_shader_col_format = col_format;
+
+       /* If the i-th target format is set, all previous target formats must
+        * be non-zero to avoid hangs.
+        */
+       num_targets = (util_last_bit(blend->spi_shader_col_format) + 3) / 4;
+       for (unsigned i = 0; i < num_targets; i++) {
+               if (!(blend->spi_shader_col_format & (0xf << (i * 4))))
+                       blend->spi_shader_col_format |= V_028714_SPI_SHADER_32_R << (i * 4);
+       }
 }
 
 static bool