From 926abff21a8f29ef159a3ac893b05c6e50e043c3 Mon Sep 17 00:00:00 2001
From: Jon Bloomfield <jon.bloomfield@intel.com>
Date: Thu, 20 Sep 2018 09:45:10 -0700
Subject: drm/i915/cmdparser: Ignore Length operands during command matching
Git-commit: 926abff21a8f29ef159a3ac893b05c6e50e043c3
Patch-mainline: v5.4-rc8
References: bsc#1152489

Some of the gen instruction macros (e.g. MI_DISPLAY_FLIP) have the
length directly encoded in them. Since these are used directly in
the tables, the Length becomes part of the comparison used for
matching during parsing. Thus, if the cmd being parsed has a
different length to that in the table, it is not matched and the
cmd is accepted via the default variable length path.

Fix by masking out everything except the Opcode in the cmd tables

Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/i915/i915_cmd_parser.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 365eea2b95bd..d78debed06e2 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -189,7 +189,7 @@ struct drm_i915_cmd_table {
 #define CMD(op, opm, f, lm, fl, ...)				\
 	{							\
 		.flags = (fl) | ((f) ? CMD_DESC_FIXED : 0),	\
-		.cmd = { (op), ~0u << (opm) },			\
+		.cmd = { (op & ~0u << (opm)), ~0u << (opm) },	\
 		.length = { (lm) },				\
 		__VA_ARGS__					\
 	}
-- 
2.28.0