ac: fix num_good_cu_per_sh for harvested chips

Cc: 19.2 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

diff --git a/src/amd/common/ac_gpu_info.c b/src/amd/common/ac_gpu_info.c
index b5e0b84..689ef27 100644 (file)
--- a/src/amd/common/ac_gpu_info.c
+++ b/src/amd/common/ac_gpu_info.c
@@ -554,6 +554,12 @@ bool ac_query_gpu_info(int fd, void *dev_p,
        info->num_good_cu_per_sh = info->num_good_compute_units /
                                   (info->max_se * info->max_sh_per_se);
 
+       /* Round down to the nearest multiple of 2, because the hw can't
+        * disable CUs. It can only disable whole WGPs (dual-CUs).
+        */
+       if (info->chip_class >= GFX10)
+               info->num_good_cu_per_sh -= info->num_good_cu_per_sh % 2;
+
        memcpy(info->si_tile_mode_array, amdinfo->gb_tile_mode,
                sizeof(amdinfo->gb_tile_mode));
        info->enabled_rb_mask = amdinfo->enabled_rb_pipes_mask;