intel/gen_decoder: return -1 for unknown command formats

Decoding with aubinator encountered a command of 0xffffffff. With the
previous code, it caused aubinator to jump 255 + 2 dwords to start
decoding again.

Instead we can attempt to detect the known instruction formats. If the
format is not recognized, then we can advance just 1 dword.

v2:
 * Update aubinator_error_decode
 * Actually convert the length variable returned into a *signed* integer
   in aubinator.c, intel_batchbuffer.c and aubinator_error_decode.c.

Signed-off-by: Jordan Justen <[email protected]>
Acked-by: Lionel Landwerlin <[email protected]>

1 files changed, 4 insertions, 3 deletions

diff --git a/src/intel/tools/aubinator.c b/src/intel/tools/aubinator.c
index cae578babac..05d932ea6c7 100644
--- a/src/intel/tools/aubinator.c
+++ b/src/intel/tools/aubinator.c
@@ -682,17 +682,18 @@ static void
 parse_commands(struct gen_spec *spec, uint32_t *cmds, int size, int engine)
 {
    uint32_t *p, *end = cmds + size / 4;
-   unsigned int length, i;
+   int length, i;
    struct gen_group *inst;
 
    for (p = cmds; p < end; p += length) {
       inst = gen_spec_find_instruction(spec, p);
+      length = gen_group_get_length(inst, p);
+      assert(inst == NULL || length > 0);
+      length = MAX2(1, length);
       if (inst == NULL) {
          fprintf(outfile, "unknown instruction %08x\n", p[0]);
-         length = (p[0] & 0xff) + 2;
          continue;
       }
-      length = gen_group_get_length(inst, p);
 
       const char *color, *reset_color = NORMAL;
       uint64_t offset;