freedreno/a6xx: Add nolrzfc debug option

Add option to disable lrz fast-clear.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32786>

src/gallium/drivers/freedreno/a6xx/fd6_resource.cc

@@ -268,7 +268,8 @@ setup_lrz(struct fd_resource *rsc)
     * on A7XX (HW limitation)
     */
    bool has_lrz_fc = screen->info->a6xx.enable_lrz_fast_clear &&
-                     lrz_fc_size <= fd_lrzfc_layout<CHIP>::FC_SIZE;
+                     lrz_fc_size <= fd_lrzfc_layout<CHIP>::FC_SIZE &&
+                     !FD_DBG(NOLRZFC);
 
    /* Allocate a LRZ fast-clear buffer even if we aren't using FC, if the
     * hw is re-using this buffer for direction tracking

src/gallium/drivers/freedreno/freedreno_screen.c

@@ -62,6 +62,7 @@ static const struct debug_named_value fd_debug_options[] = {
    {"sysmem",    FD_DBG_SYSMEM,   "Use sysmem only rendering (no tiling)"},
    {"serialc",   FD_DBG_SERIALC,  "Disable asynchronous shader compile"},
    {"shaderdb",  FD_DBG_SHADERDB, "Enable shaderdb output"},
+   {"nolrzfc",   FD_DBG_NOLRZFC,  "Disable LRZ fast-clear"},
    {"flush",     FD_DBG_FLUSH,    "Force flush after every draw"},
    {"inorder",   FD_DBG_INORDER,  "Disable reordering for draws/blits"},
    {"bstat",     FD_DBG_BSTAT,    "Print batch stats at context destroy"},

src/gallium/drivers/freedreno/freedreno_util.h

@@ -67,7 +67,7 @@ enum fd_debug_flag {
    FD_DBG_SERIALC      = BITFIELD_BIT(10),
    FD_DBG_SHADERDB     = BITFIELD_BIT(11),
    FD_DBG_FLUSH        = BITFIELD_BIT(12),
-   /* BIT(13) */
+   FD_DBG_NOLRZFC      = BITFIELD_BIT(13),
    FD_DBG_INORDER      = BITFIELD_BIT(14),
    FD_DBG_BSTAT        = BITFIELD_BIT(15),
    FD_DBG_NOGROW       = BITFIELD_BIT(16),