[Intel-gfx] [PATCH 2/3] drm/i915/icl: Switch to using 12 deep CSB status FIFO

[Mika Kuoppala]

Now when we can support variable csb fifo sizes, disable legacy mode.
By disabling legacy we hope to get better hw testing coverage by
assuming everyone else have switched over.

v2: rebase

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Kelvin Gardiner <kelvin.gardiner at intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_lrc.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index bd35ac3b7b77..039e2a54b1fc 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1659,17 +1659,9 @@ static void enable_execlists(struct intel_engine_cs *engine)
 
 	I915_WRITE(RING_HWSTAM(engine->mmio_base), 0xffffffff);
 
-	/*
-	 * Make sure we're not enabling the new 12-deep CSB
-	 * FIFO as that requires a slightly updated handling
-	 * in the ctx switch irq. Since we're currently only
-	 * using only 2 elements of the enhanced execlists the
-	 * deeper FIFO it's not needed and it's not worth adding
-	 * more statements to the irq handler to support it.
-	 */
 	if (INTEL_GEN(dev_priv) >= 11)
 		I915_WRITE(RING_MODE_GEN7(engine),
-			   _MASKED_BIT_DISABLE(GEN11_GFX_DISABLE_LEGACY_MODE));
+			   _MASKED_BIT_ENABLE(GEN11_GFX_DISABLE_LEGACY_MODE));
 	else
 		I915_WRITE(RING_MODE_GEN7(engine),
 			   _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE));
@@ -2254,7 +2246,10 @@ static int logical_ring_init(struct intel_engine_cs *engine)
 	execlists->csb_write =
 		&engine->status_page.page_addr[intel_hws_csb_write_index(i915)];
 
-	execlists->csb_size = GEN8_CSB_ENTRIES;
+	if (INTEL_GEN(engine->i915) < 11)
+		execlists->csb_size = GEN8_CSB_ENTRIES;
+	else
+		execlists->csb_size = GEN11_CSB_ENTRIES;
 
 	reset_csb_pointers(execlists);
 
-- 
2.17.1