[Intel-gfx] [PATCH] drm/i915: Catch non-existent registers in find_fw_domain

[Joonas Lahtinen]

Add WARN_ON to find_fw_domain to registers related to uninitialized
hardware.

Cc: Imre Deak <imre.deak at intel.com>
Cc: Wang Elaine <elaine.wang at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_uncore.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 07779d0..b20b58e 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -625,7 +625,12 @@ find_fw_domain(struct drm_i915_private *dev_priv, u32 offset)
 			dev_priv->uncore.fw_domains_table_entries,
 			fw_range_cmp);
 
-	return entry ? entry->domains : 0;
+	if (!entry)
+		return 0;
+
+	WARN_ON(entry->domains & ~dev_priv->uncore.fw_domains);
+
+	return entry->domains;
 }
 
 static void
-- 
2.7.4