[PATCH] intel: Do not assert on unknown chips in drm_intel_decode_context_alloc

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

There is this long standing nit of igt/tools/intel_error_decode asserting
when you feed it an error state from a GPU the local libdrm does not know
of.

To fix this I need a tweak in drm_intel_decode_context_alloc to make it
not assert but just return NULL (which seems an already possible return
value).

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 intel/intel_decode.c | 39 +++++++++++++++++++++------------------
 1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/intel/intel_decode.c b/intel/intel_decode.c
index e0a516644314..be6f77984d65 100644
--- a/intel/intel_decode.c
+++ b/intel/intel_decode.c
@@ -3815,32 +3815,35 @@ drm_public struct drm_intel_decode *
 drm_intel_decode_context_alloc(uint32_t devid)
 {
 	struct drm_intel_decode *ctx;
+	int gen = 0;
 
-	ctx = calloc(1, sizeof(struct drm_intel_decode));
-	if (!ctx)
-		return NULL;
-
-	ctx->devid = devid;
-	ctx->out = stdout;
-
-	if (intel_get_genx(devid, &ctx->gen))
+	if (intel_get_genx(devid, &gen))
 		;
 	else if (IS_GEN8(devid))
-		ctx->gen = 8;
+		gen = 8;
 	else if (IS_GEN7(devid))
-		ctx->gen = 7;
+		gen = 7;
 	else if (IS_GEN6(devid))
-		ctx->gen = 6;
+		gen = 6;
 	else if (IS_GEN5(devid))
-		ctx->gen = 5;
+		gen = 5;
 	else if (IS_GEN4(devid))
-		ctx->gen = 4;
+		gen = 4;
 	else if (IS_9XX(devid))
-		ctx->gen = 3;
-	else {
-		assert(IS_GEN2(devid));
-		ctx->gen = 2;
-	}
+		gen = 3;
+	else if (IS_GEN2(devid))
+		gen = 2;
+
+	if (!gen)
+		return NULL;
+
+	ctx = calloc(1, sizeof(struct drm_intel_decode));
+	if (!ctx)
+		return NULL;
+
+	ctx->devid = devid;
+	ctx->gen = gen;
+	ctx->out = stdout;
 
 	return ctx;
 }
-- 
2.25.1