[igt-dev] [PATCH i-g-t] tests/i915/WA: Mark FF_MODE2 as WO for TGL

[Ramalingam C]

On TGL till B0 stepping FF_MODE2(0x6604) register is not readable. But
we need to program this register for Wa_1604555607 for better
performance. Hence to skip the verification attempt on this register
through read, we are marking this register as write only.

As of now I have marked this register as write only for gen12, we can
narrow it down to TGL <= B0, if we can retrieve the stepping of the
platform at IGT.

Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
cc: Chris Wilson <chris at chris-wilson.co.uk>
---
 tests/i915/gem_workarounds.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/i915/gem_workarounds.c b/tests/i915/gem_workarounds.c
index dd6316ea3b4e..57d307b9991b 100644
--- a/tests/i915/gem_workarounds.c
+++ b/tests/i915/gem_workarounds.c
@@ -51,8 +51,8 @@ static struct write_only_list {
 	unsigned int gen;
 	uint32_t addr;
 } wo_list[] = {
-	{ 10, 0xE5F0 } /* WaForceContextSaveRestoreNonCoherent:cnl */
-
+	{ 10, 0xE5F0 }, /* WaForceContextSaveRestoreNonCoherent:cnl */
+	{ 12, 0x6604 }	/* FIXME: Stepping > B0 might be readable */
 	/*
 	 * FIXME: If you are contemplating adding stuff here
 	 * consider this as a temporary solution. You need to
-- 
2.20.1