asahi: Fix disk cache disable with AGX_MESA_DEBUG

We go to initialize the disk cache before we've compiled any shaders so
agx_compiler_debug is 0 at this point. Don't try to read it, instead go through
sa safe getter that will do the right thing.

Fixes: 5e9538c12e ("agx: isolate compiler debug flags")
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22891>
(cherry picked from commit e9b471d1b3)

.pick_status.json

@@ -1165,7 +1165,7 @@
         "description": "asahi: Fix disk cache disable with AGX_MESA_DEBUG",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "5e9538c12e0f564af888e2d2c1804e960b9492ca"
     },

src/asahi/compiler/agx_compile.c

@@ -39,6 +39,12 @@ DEBUG_GET_ONCE_FLAGS_OPTION(agx_compiler_debug, "AGX_MESA_DEBUG",
 
 int agx_compiler_debug = 0;
 
+uint64_t
+agx_get_compiler_debug(void)
+{
+   return debug_get_option_agx_compiler_debug();
+}
+
 #define DBG(fmt, ...)                                                          \
    do {                                                                        \
       if (agx_compiler_debug & AGX_DBG_MSGS)                                   \
@@ -2360,7 +2366,7 @@ agx_compile_shader_nir(nir_shader *nir, struct agx_shader_key *key,
                        struct util_dynarray *binary,
                        struct agx_shader_info *out)
 {
-   agx_compiler_debug = debug_get_option_agx_compiler_debug();
+   agx_compiler_debug = agx_get_compiler_debug();
 
    memset(out, 0, sizeof *out);
 

src/asahi/compiler/agx_compiler.h

@@ -809,6 +809,8 @@ struct agx_occupancy {
 
 struct agx_occupancy agx_occupancy_for_register_count(unsigned halfregs);
 
+extern int agx_compiler_debug;
+
 #ifdef __cplusplus
 } /* extern C */
 #endif

src/asahi/compiler/agx_debug.h

@@ -27,7 +27,7 @@ enum agx_compiler_dbg {
 };
 /* clang-format on */
 
-extern int agx_compiler_debug;
+uint64_t agx_get_compiler_debug(void);
 
 #ifdef __cplusplus
 } /* extern C */

src/gallium/drivers/asahi/agx_disk_cache.c

@@ -134,7 +134,7 @@ void
 agx_disk_cache_init(struct agx_screen *screen)
 {
 #ifdef ENABLE_SHADER_CACHE
-   if (agx_compiler_debug || screen->dev.debug)
+   if (agx_get_compiler_debug() || screen->dev.debug)
       return;
 
    const char *renderer = screen->pscreen.get_name(&screen->pscreen);